Abstract: National High-Speed Rail Grid (4+4) Passenger Dedicated Lines (PDL) Railway Planning, covering all provincial capital cities and more than 90% cities with populations of more than 500,000, will be up and running in 2015. Accessibility by high speed railway network has become a hot topic in the accessibility research field. In this paper, based on review of the methods used by other researchers, the shortest time distance matrix between provincial capital cities was chosen to analyze inter-provincial accessibility by conventional railway network and by high-speed railway network, and weighted average travel time was used to analyze inter-provincial accessibility and spatial pattern in the high-speed railway time. Results are shown as fellows: (1) Inter-provincial accessibility by conventional railway network obtained with shortest time distance (including transfer and short-stay) has a "center-periphery" spatial pattern, with Zhengzhou-Wuhan as the center and other provinces as peripheries. The accessibility decreases from center to peripheries in circular gradients. The dominant factors affecting the accessibility are network pattern, node location and train organization, as Beijing has higher accessibility with radial rail network. (2) Inter-provincial accessibility by high-speed railway network also has a "center-periphery" pattern, whileWuhan is more convenient than Zhengzhou. Passenger Dedicated Lines have shortened inter- provincial travel time and doubled the 2% areas of best accessibility (from 5.3×10⁴ km² to 10.8×10⁴ km²), showing the effects of high-speed railway network. The average travel distance of each capital city is 60,000 kilometers by both conventional network and high-speed railway network, but the latter only costs half of total travel time as the former, while the area of the best accessibility is 108,000 square kilometers. (3) High-speed railway network will equalize inter-province accessibility, as standard deviation of accessibility coefficient is less than conventional railway network. Remote regions such as Yunnan and Fujian had the biggest improvement in accessibility while the center provinces had littles change.

Key words: accessibility, China, high speed railway, shortest time distance, spatial pattern