Train working diagram (TWD) plays a very important role in railway transportatio n, and it is the synthetic plan and foundation of railway transport organization .TWD worked out with computer is a practical and difficult project, which must b e solved as early as possible. Through many years research and practice,TWD work ed out with computer makes great progress not only in theory but also in practic e, which breaks into several periods, such as double track line,single track li ne,railway terminal area and railway network. Jing—Hu high-speed railway line, being programmed and built in the Tenth ″Fiv e Years Plan″, will take the mode of high-speed train and middle-speed train sharing high-speed railway line at beginning. So this results in big problem in theory and method of TWD between high-speed railway line and the existing rail way. Based on analyzing production and literatures of China and overseas about T WD of high-speed railway line and the existing railway, this paper establishes the theory of TWD of high-speed and middle-speed train using the same high-sp eed railway network train working diagram (HSRNTWD) .The main contents of this p aper are: (1) This paper analyzes and summarizes production and existing problems of TWD o f high-speed railway line and the existing railway in China and abroad. It desc ribes the differences and common grounds between TWD of the existing railway and high-speed railway line from many core problems such as aim, order and policy of TWD. (2) Based on the transportation mode of high-speed railway line and absorbed th e experience of TWD of the existing railway, this paper puts forward fundamental theory of TWD of high-speed railway line based on railway network, discusses a im, order and hierarchy of TWD of high-speed railway line. (3) This paper establishes the theory of high-speed railway line based on railw ay network from microscopic layer and macroscopic layer. Macroscopic layer is us ed to describe the network structure and relation of railway line, and calculate
