Abstract: Most of China's provincial capitals are located in railway hubs. The study of railway accessibility of provincial capitals is of great significance for adjusting train operation plans, improving passenger travel experience, optimizing railway network layout and guiding long-term route planning and construction. Based on the analysis of the existing urban accessibility measurement methods and their applicability, a new railway accessibility index for provincial capitals is proposed based on the development pattern and situation of China's railway network. Using historical data from the passenger ticketing system, a comprehensive and in-depth analysis of the changes in railway accessibility of provincial capitals in China from 2012 to 2021 is conducted, the causes and trends of the changes in railway accessibility of provincial capitals in each period are explored. Meanwhile, the provincial capitals that have a significant gap with their ineighboring provincial capitals in railway accessibility can be accurately identified and suggerstions for improvement are put forward from the aspects of ralway line planning and construction as well as train diagram adjustment.