The rail transportation has become an important conveyance carrying passengers and cargos. Railway network which is comprised of stations and railways influences the hierarchical structure and distribution pattern of the national urban system. This paper screens out the study objects including 186 prefectural-level cities having starting trains by timetable, and analyzes the hierarchical structure and distribution pattern of the urban system based on the data of starting trains. This paper demonstrates that the number of railway trains at starting station is positively correlated with the hierarchy of urban system. On this basis, it uses the methods of charts discriminance and the clustering analysis to classify all the 186 cities into four hierarchies. There are 3 national central cities, 8 regional central cities, 30 sub-regional central cities and 145 local central cities. From a unique perspective of railway network, the article reveals the following characteristics of the hierarchical structure and distribution pattern of Chinese urban system. (1) The urban hierarchy system presents a typical pyramidal structure, which means the higher the hierarchy of the cities is in the system, the smaller the number of the cities is. (2) The administrative, topographical and economic factors affect the railway network markedly, consequently affect the urban hierarchy system greatly. (3) The distribution of cities in eastern China is different from that in western China, which means the higher-hierarchy cities are mainly distributed in the east, and the railways of the west cities are mostly in east-west direction. (4) High-hierarchy cities are evenly distributed in eastern China, which constitutes the fundamental framework of Chinese urban railway network and coincides with the "T"-shaped development strategy of the national land. (5) Six pairs of dual-core structure of urban patterns have been formed among high-hierarchy central cities due to the close connection of railway network.