The data utilized in this study were primarily sourced from Chinese Fourth (1990), Fifth (2000), Sixth (2010), and Seventh (2020) National Population Censuses. While the Chinese government officially recognizes 56 ethnic groups, the census data also include populations categorized as “unidentified ethnicities” and “foreigners acquiring Chinese citizenship.” Consequently, our analysis encompasses 58 ethnic categories. For methodological rigor, the study scope was constrained to mainland Chinese 31 provincial-level administrative units (municipalities, provinces, and autonomous regions), excluding Hong Kong, Macao, and Taiwan due to data availability limitations and statistical consistency requirements. The census provides ethnic population statistics across four residential dimensions: aggregate provincial totals, urban districts, town, and rural areas. To align with contemporary urbanization research paradigms, we consolidated urban and town populations into a unified “urban settlement” category. This aggregation yielded three distinct analytical dimensions for measuring cultural diversity: aggregate cultural diversity, urban cultural diversity, and rural cultural diversity.

Analysis based on four national population censuses reveals that aggregate cultural diversity demonstrated a consistent upward trend, increasing from 0.51 in 1990 to 0.55 in 2020 (Figure 1). This progression indicates enhanced cultural integration and intensified interethnic exchanges nationwide. From an urban–rural perspective, there are notable disparities in cultural diversity. The rural cultural diversity has shown the fastest growth rate, increasing rapidly from 0.50 in 1990 (slightly below the national average) to 0.74 in 2020, with the most rapid acceleration occurring during 1990–2000. While urban cultural diversity remains relatively lower in absolute terms, its growth rate exceeds the aggregate cultural diversity, rising from 0.32 in 1990 to 0.44 in 2020. Particularly during 2010–2020, the urban cultural diversity increased by 0.08 points, indicating a narrowing gap with the aggregate cultural diversity.

Figure 2 illustrates the distribution of cultural diversity indices across Chinese provinces at the aggregate, urban, and rural levels between 1990 and 2020. As shown in Figures 2a,b, the development of aggregate cultural diversity exhibited distinct regional stratification, following a consistent spatial pattern of Western > Northeastern > Central > Eastern regions. The highest diversity levels (aggregate cultural diversity > 1.0) were observed in western provinces including Yunnan, Guizhou, Qinghai, and Xinjiang, where complex topography has fostered multi-ethnic concentrations and consequently higher aggregate cultural diversity. in contrast, eastern and central provinces generally demonstrated lower aggregate cultural diversity, with Shaanxi, Shanxi, Shandong, Henan, Anhui, Jiangsu, Shanghai, Jiangxi, and Fujian persistently maintaining extremely low levels (aggregate cultural diversity < 0.2) due to their predominant Han population concentrations. Temporal analysis revealed notable transitions: between 1990 and 2020, Hebei, Tianjin, Jiangsu, Hubei, and Guangdong progressed from extremely low to relatively low levels (0.2 < aggregate cultural diversity < 0.4), while Gansu, Tibet, and Hunan advanced from relatively low to low levels (0.4 < aggregate cultural diversity < 0.6). Notably, Jilin was the only province exhibiting a decline in diversity ranking. Most provinces demonstrated increasing trends (except Liaoning, Jilin, Heilongjiang, and Xinjiang, see Table 1), though without categorical shifts. The most rapid increases (>0.1) occurred in Tibet, Zhejiang, Guangdong, and Qinghai - with Tibet and Qinghai building upon their already high baseline diversity, while Zhejiang and Guangdong improved from initially low levels. This spatial–temporal pattern suggests that western provinces’ aggregate cultural diversity gains may reflect targeted regional development policies promoting ethnic integration, whereas eastern provinces’ growth likely stems from migration-driven demographic diversification in major population inflow regions like Zhejiang and Guangdong.

Figures 2c,d reveal that the spatial distribution pattern of urban cultural diversity generally aligns with the overall diversity pattern, maintaining the regional hierarchy of Western > Northeastern > Central > Eastern China. However, the number of provinces with high-level urban cultural diversity was lower than the aggregate cultural diversity. In 1990, only Xinjiang and Guizhou reached the highest diversity category, both with indices below 1, while provinces with extremely low urban cultural diversity were markedly more prevalent in urban areas compared to the aggregate cultural diversity pattern. Nevertheless, urban cultural diversity demonstrated faster developmental momentum, as evidenced by the 2020 distribution of highest-level diversity provinces converging with the aggregate cultural diversity pattern and a reduction in extremely low-diversity provinces. The urban cultural diversity trends exhibited greater variation across provinces (Table 1), with more provinces showing declining urban cultural diversity (Jilin, Heilongjiang, Hainan, Shaanxi, Shanxi, Anhui, and Henan) compared to the aggregate cultural diversity trend, suggesting weaker attractiveness to minority populations during these provinces’ urbanization processes. Conversely, eight provinces achieved growth rates exceeding 0.1, reflecting substantial ethnic population migration to urban areas during urbanization. This dual pattern highlights the complex interplay between urban development and ethnic demographic dynamics across different regions.

As shown in Figures 2e,f, the spatial distribution of aggregate cultural diversity similarly follows the regional pattern of Western > Northeastern > Central > Eastern China, yet maintains higher average levels compared to both the aggregate cultural diversity and urban cultural diversity measures. Further analysis of rural cultural diversity (Table 1) reveals that only three provinces - Jilin, Heilongjiang, and Henan - exhibited declining trends, attributable to substantial rural-to-urban migration and population outflow that diminished local diversity. In contrast, 12 provinces demonstrated growth rates exceeding 0.1, a markedly higher proportion than observed in either aggregate cultural diversity and urban cultural diversity, indicating the most pronounced dynamic changes occurring at the rural level. This pattern underscores the heightened sensitivity of rural cultural diversity to demographic shifts, where substantial ethnic population retention and redistribution have driven more rapid diversification compared to urban areas. The differential trends between declining and rapidly growing provinces highlight the complex interplay between rural depopulation and cultural transformation across Chinese regional contexts.

As shown in Figure 3, Gini coefficient of provincial cultural diversity demonstrated a consistent declining trend across aggregate, urban, and rural dimensions from 1990 to 2020, decreasing from 0.558, 0.501, and 0.560 to 0.487, 0.471, and 0.518 respectively, indicating a sustained reduction in cultural diversity disparities at the national level and reflecting progressive integration of multi-ethnic populations. Regional analysis reveals distinct spatial patterns, with regional disparities following the hierarchy of Central > Eastern > Western > Northeastern China. The Eastern region exhibited continuous convergence across all measurement dimensions, suggesting accelerating ethnic integration, while the Northeastern region showed opposite trends with widening disparities throughout the study period. The Central region displayed divergent trajectories - initial increase followed by decrease in aggregate and rural dimensions contrasted with persistent growth in urban areas, whereas the Western region maintained relative stability, with modest reductions in aggregate and rural cultural diversity gaps. These patterns collectively demonstrate the complex, dimension-specific nature of China’s regional cultural diversity evolution during its urbanization process.

Figure 4 presents interregional disparities across aggregate, urban, and rural dimensions, revealing that the greatest differences exist between Eastern and Central China, which exhibit divergent trends across measurement dimensions: while showing decreasing trends at both provincial and rural levels, these disparities demonstrate an increasing pattern in urban areas. The second most pronounced differences occur between Western and Eastern regions, displaying consistent declining trends throughout the study period. Other regional differentials exhibit certain fluctuations, with Northeast-Central and Northeast-East interregional gaps demonstrating decreasing trends across all three dimensions, whereas Northeast-West disparities show persistent increases in aggregate, urban, and rural measurements. This multidimensional analysis highlights the complex spatial–temporal dynamics of China’s regional cultural diversity patterns, where the direction and magnitude of interregional differences vary substantially depending on both geographic pairing and measurement dimension. These results suggest that regional integration processes have progressed unevenly across different spatial scales and sectoral contexts.

The decomposition results of Dagum Gini coefficients presented in Table 2 demonstrate that inter-regional disparities constitute the primary source of cultural diversity differences in China, accounting for 63.4–70.3% of total variation, followed by intra-regional differences (21.6–23.9%), while the contribution rate of transvariation density remains the lowest (8.1–12.7%). Temporally, the inter-regional disparities exhibit distinct trajectories across dimensions: showing an initial decline followed by an increase at both provincial and rural levels (1990–2000 decrease, 2000–2020 increase), while displaying an opposite pattern of first increasing then slightly decreasing in urban areas (1990–2010 rise, 2010–2020 modest decline), suggesting that reducing inter-regional disparities among the four major geographic divisions should be the focal point for promoting cultural integration in the foreseeable future. Particularly noteworthy is the consistent 10% average contribution rate of transvariation across all three dimensions, which not only confirms the virtual absence of sample overlap but also verifies the evident hierarchical development characteristics of cultural diversity levels among provinces, thereby providing crucial evidence for formulating differentiated regional cultural policies.

As shown in Table 3, the global Moran’s I indices for China’s cultural diversity across all three dimensions (aggregate, urban, and rural) are consistently positive and demonstrate an upward trend, indicating statistically significant spatial autocorrelation with intensifying clustering patterns in the distribution of cultural diversity. Notably, the urban dimension exhibits the highest Moran’s I values, suggesting that urbanization processes have played a particularly influential role in reshaping the spatial configuration of cultural diversity. These results reveal that cultural diversity is not randomly distributed but rather displays increasingly concentrated spatial patterns, with urban areas serving as primary drivers of this spatial reorganization through their capacity to attract and integrate diverse populations. The strengthening spatial dependence highlights the emergence of distinct cultural regions shaped by both historical settlement patterns and contemporary migration flows under rapid urbanization.

Figure 5 presents the local spatial associations of cultural diversity, revealing that provinces with statistically significant local autocorrelation are predominantly clustered in “High-High,” “Low-Low,” and “Low-High” patterns (all p < 0.05), demonstrating pronounced spatial agglomeration effects in the distribution of cultural diversity across Chinese provinces. The spatial clustering patterns exhibit remarkable consistency across aggregate, urban, and rural dimensions, with “High-High” clusters primarily concentrated in western regions and “Low-Low” aggregations predominantly located in central and eastern areas. During the study period, both “High-High” and “Low-Low” clusters showed expansion, while “Low-High” transitional zones experienced contraction, indicating intensifying spatial polarization of cultural diversity characteristics and strengthening path dependence in regional cultural development trajectories. These patterns collectively suggest that cultural diversity is evolving toward more defined spatial demarcations with increasingly homogeneous intra-regional and heterogeneous inter-regional characteristics.

Figure 6 reveals distinct patterns in the gravitational linkage intensity of cultural diversity across aggregate, urban, and rural dimensions, with rural areas exhibiting the strongest interregional connections, followed by the aggregate level, while urban dimensions demonstrate the weakest linkages. Spatially, all three dimensions share similar distribution characteristics: weak gravitational associations predominantly cluster in central and eastern regions characterized by Han-dominant populations with limited ethnic minority distribution, where restricted population mobility during the early reform and opening-up period further constrained cultural integration with other regions. Moderate linkages primarily form a “C-shaped” pattern across northern, western, and southwestern areas, whereas strong and very strong connections concentrate between specific provincial pairs including Gansu-Qinghai, Yunnan-Guizhou, and Guizhou-Guangxi. Temporally, all three dimensions show enhanced gravitational associations among provinces throughout the study period, particularly in northern, western and southern regions, reflecting intensified cultural exchanges and population mobility patterns under Chinese urbanization and regional development policies. These spatial–temporal dynamics collectively demonstrate how historical demographic distributions, contemporary migration trends, and uneven regional development have jointly shaped the evolving network of interprovincial cultural interactions.

China’s cultural diversity exhibits a distinct spatial pattern characterized by higher levels in western and northeastern regions compared to relatively lower diversity in central and eastern areas, a finding consistent with previous research (Chen, 2023; Qu and Meng, 2014). This spatial differentiation fundamentally stems from the country’s complex natural geography. Topographically, Chinese three-terrace configuration features predominantly plateau and mountainous terrain in the western first and second terraces, where historically these rugged landscapes served as natural barriers that limited ethnic integration and fostered the development of distinct cultural traditions in relatively isolated environments. However, the third terrace’s plains and hills facilitated large-scale agriculture and became the heartland of Han Chinese settlement. Climatically, spanning nearly 50 degrees of latitude with six temperature zones (from cold temperate to tropical) plus the Qinghai-Tibet Plateau vertical climate zone, combined with precipitation gradients, the country has developed diverse ecosystems including northern arid/semi-arid pastoral grasslands, western alpine pastoral regions, and southern humid agricultural areas. It is through this interplay of topographic and climatic factors that China gradually formed its current cultural geography - a low-cultural diversity Han Chinese core in central-eastern regions, grading into high-diversity minority concentration zones extending westward, northward, and southward, exemplifying the profound, long-term interaction between natural environments and socio-cultural development.

From a temporal evolution perspective, China’s cultural diversity has demonstrated a continuous growth trend across aggregate, urban, and rural dimensions, indicating progressive integration of ethnic populations, a phenomenon closely tied to national minority fertility policies. Since the nationwide implementation of family planning policies in the mid-1970s, ethnic autonomous regions in western China successively formulated localized family planning regulations that implemented more lenient childbirth provisions for minority groups compared to the Han majority (Cheng and Chen, 2008; Zhang, 2011). This policy differential has resulted in substantially higher population growth rates in minority regions relative to the national average, with the minority population proportion increasing from 8.04% in 1990 to 8.89% by 2020. The expanding minority population has greatly contributed to ethnic integration and enhanced cultural diversity. Initially, this demographic shift primarily manifested in accelerated rural cultural diversity growth, as minority populations were traditionally concentrated in rural areas. However, with rapid urbanization in recent years, cities have increasingly attracted minority migrants, consequently driving faster development of urban cultural diversity. This dual rural–urban dynamic reflects the complex interplay between demographic policies, migration patterns, and spatial transformation in shaping Chinese evolving cultural landscape.

From a spatial evolution perspective, China’s cultural diversity has shown consistent increasing trends in western, central, and eastern regions, while demonstrating continuous decline in the northeast - a phenomenon attributed to severe negative population growth in this region resulting from both rapidly declining birth rates and accelerated outmigration (Chen and Wu, 2024; Zhang and Wang, 2023). Despite overall growth in other regions, spatial imbalances persist: at the aggregate level, diversity growth rates follow an eastern>western>central pattern; urban dimensions exhibit western>eastern>central progression; while rural areas display western>central>eastern gradients. This spatial heterogeneity reflects Chinese intensifying interprovincial migration patterns, with eastern provinces emerging as primary destinations - the proportion of both Han and minority interprovincial migrants flowing eastward increased dramatically from 54.8 and 49.0% in 1990 to 80.5 and 78.8% by 2010, respectively, (Huang and Duan, 2022), substantially boosting eastern regions’ aggregate cultural diversity. Urban cultural diversity growth primarily stems from rural-to-urban migration, particularly impactful in western cities that receive disproportionate flows from minority-concentrated rural areas (Jiao, 2014). Meanwhile, rural cultural diversity patterns remain fundamentally shaped by the original ethnic distribution, maintaining a distinct west–east decreasing gradient that correlates with historical settlement patterns. These multidimensional dynamics collectively illustrate how migration selectivity, urbanization pressures, and regional development disparities interact to reshape China’s cultural geography.

Since the implementation of reform and opening-up policies, China has witnessed the gradual establishment and improvement of its market economy system, leading to massive population migration from rural to urban areas and from central-western to eastern regions under the pull forces of investment and economic opportunities (Wang et al., 2023). Coastal provinces, in particular, have experienced rapid economic development that enhanced their attractiveness to diverse talents, with Guangdong and Zhejiang emerging as top destinations for minority migrants by 2020 (Xu and Wang, 2022), consequently boosting their cultural diversity levels. Our findings confirm that eastern regions demonstrate the fastest growth rate in average cultural diversity, thereby contributing to reduced interprovincial diversity disparities nationwide. However, regional variations persist - while intra-regional differences continue to decline in eastern areas due to their strong economic performance and capacity to attract diverse migrant populations that help balance local cultural diversity (Ma et al., 2024). Northeastern regions exhibit the opposite trend of increasing intra-regional disparities, likely resulting from differential outmigration patterns among minority groups (Liu et al., 2024) that disrupt previously balanced ethnic distributions. These diverging intra-regional dynamics ultimately contribute to emerging inter-regional differences, collectively shaping the evolving landscape of Chinese provincial cultural diversity patterns. The contrasting regional trajectories highlight how economic development disparities and varying capacities to absorb migrant populations interact to produce complex spatial differentiations in cultural diversity across Chinese provinces.

Despite China’s continuous improvement in cultural diversity, significant imbalances persist between urban and rural areas and across different regions. To further promote the regional development of cultural diversity and enhance cultural exchange and integration among regions, the following policy recommendations are proposed:

Firstly, sustained encouragement and support should be provided for fertility policies targeting ethnic minorities in western and northeastern regions. Local government support should be strengthened through measures such as childbirth subsidies, tax reductions, and expanded healthcare coverage (Zhang, 2011). For ethnic groups with very small populations, such as the Oroqen and Derung, all restrictions on birth numbers should be lifted to facilitate the preservation of ethnic minority cultures (Yang, 2023).

Secondly, in response to the ongoing regional mobility of ethnic minorities nationwide, active promotion of migration flows from western and northeastern regions to central and eastern areas should be implemented. However, these populations may face challenges such as employment discrimination, housing inequality, limited access to education, and inadequate healthcare (Zhong and Shi, 2025). Therefore, destination governments should prioritize enhancing intercultural integration by implementing comprehensive policy safeguards and social services addressing employment, children’s education, and healthcare for migrant ethnic minority groups.

Thirdly, as cultural diversity constitutes an integral part of regional cultural development, systematic efforts are needed to preserve and disseminate migrant minority cultures. Coordinated actions between local governments and research institutions are required to protect cultural diversity through policies that enhance intercultural connections and integration (Huang et al., 2022; Ning et al., 2025). Consequently, while establishing cultural preservation as a shared social responsibility, it is essential to foster a sense of community belonging and pride. These multidimensional strategies aim to address existing disparities while leveraging opportunities for immigration-oriented cultural exchange and development.

Based on China’s 1990–2020 census data, this study measured provincial cultural diversity and analyzed its spatiotemporal evolution patterns. Additionally, it explored the strength of interregional cultural diversity connections. While the findings hold significance for promoting cultural integration and development, several limitations remain. First, cultural diversity is a highly complex concept encompassing not only ethnic/racial population diversity but also language, religion, customs, and more. The exclusive use of ethnic population proportions as a proxy indicator presents limitations. Subsequent research should integrate language (e.g., number of regional dialects), religion (e.g., number of regional religions), and cultural practices (e.g., intangible cultural heritage items) to measure cultural diversity more comprehensively. Second, cultural diversity exhibits long-term and dynamic characteristics. This study only measured Chinese cultural diversity at four time points (1990, 2000, 2010, 2020) and analyzed its spatiotemporal evolution solely at the provincial scale, whereas finer scales could capture more regional variations. Therefore, future work could involve analyses at smaller scales and over longer time series to enhance data accuracy and capture more features of regional differences. Third, the spatiotemporal evolution of cultural diversity is influenced by multiple factors, including geographical environment, policy systems, and population mobility. However, due to data accessibility and model complexity, the specific effects of these influencing factors were not quantified. Future research should incorporate more specific variables to explore their quantitative effects, constructing a comprehensive and systematic analytical framework to gain deeper insights into the spatiotemporal evolution of cultural diversity.