Purpose - Polycentricity has become a crucial spatial development strategy. This paper aims to clarify the impact and mechanism of polycentric spatial structure on the urban-rural income gap, provide better countermeasures to narrow it and make development suggestions for cities of different scales. Design/methodology/approach - Based on the panel data of Chinese cities from 2010 to 2019, this paper empirically examines the specific impact of polycentric spatial structure on the urban-rural income gap by utilizing a two-way fixed effects model. Findings - The results show that the polycentric spatial structure is favorable for reducing the urban-rural income gap, and upgrading the industrial structure and improving transportation infrastructure are important mechanisms. Moreover, the role of polycentric spatial structure is more significant in large cities. However, in small and medium-sized cities, the role of polycentric spatial structure is not significant. Research limitations/implications - The limitations of this study include two main aspects. One is that this paper only analyzes the mediating effect of industrial structure and transport infrastructure, and we do not examine other mechanisms. The second is that due to data availability, this paper uses data from 2010 to 2019, and the research period can be further extended in future studies. Practical implications - This study has policy implications for building a polycentric city network and also provides insights into the planning of cities of different scales. Social implications - The polycentric spatial structure is important for narrowing the urban-rural income gap, especially in large cities. Improvement of transportation infrastructure and upgrading of industrial structure are important mechanisms. However, the polycentric spatial structure does not play a significant role in small and medium-sized cities. Thus, the polycentric spatial structure is not suitable for every kind of city. Relevant departments should carry out urban planning according to local conditions. Originality/value - As a critical concern of urban planning, polycentricity significantly affects the urban-rural income gap. Relevant studies have analyzed the impact of polycentric spatial structure on regional income disparity, and few studies have focused on the relationship between polycentric spatial structure and the urban- rural income gap. Using city panel data in China, this paper explores the impact of polycentric spatial structure on the urban-rural income gap. Meanwhile, we test the mediating role of transportation infrastructure improvement and industrial structure upgrading. This study broadens the analysis of the urban-rural income gap's influencing factors and provides a path reference for narrowing the urban-rural income gap.
