Abstract: In the research area of urban green space (UGS), accessibility has emerged as a pivotal area of focus. Among the various analytical tools, the Gaussian two-step floating catchment area method (G2SFCA) has garnered significant academic attention due to its cutting-edge capabilities for quantitative analysis. However, there are two major limitations in current studies. First, they often overlooked the subjective perceptions of residents. Second, there was a notable deficiency in comparative analyses of different urban types at the regional scale. Taking the central and southern Liaoning urban agglomeration as a case study, we constructed a G2SFCA model that integrated both subjective and objective elements. This integrated model was employed to systematically evaluate the accessibility characteristics of UGS across cities of varying grades. The results showed that medium-grade cities exhibited the highest accessibility (99.97), followed by highgrade cities (85.40) and low-grade cities (69.46). Moreover, the spatial differentiation within cities of different grades was markedly distinct. Correlafion analysis excluding other urban-specific characteristics indicated that natural geographical conditions did not exhibit significant correlations with either average accessibility or urban grade. While social and economic factors were not significantly related to average accessibility, they were strongly correlated with urban grade. This suggested that the ranking relationship between urban grade and average accessibility was not affected by other factors. We proposed that urban green space system planning should holistically consider the regional economic development level and the spatial distribution patterns of the population, and implement differentiated strategies accordingly. High-grade cities should prioritize enhancing the quality of existing green spaces. Medium-grade cities should focus on integrating existing resources across districts. Low-grade cities should adopt a “precise supplementation” strategy, moderately developing natural resources on their peripheries. In summary, our results provide a robust scientific foundation for urban park green space planning that balanced regional integrity with urban differences, which would help formulate more targeted hierarchical construction strategies and promote the goal of achieving social equity in the distribution of green resources.

Key words: accessibility, green equity, Gaussian two-step floating catchment area method, central and southern Liaoning urban agglomeration