Abstract: The accessibility of roads in the border areas of the plateau is related to land security, social stability and economic development.The road network of Tashkurgan Tajik Autonomous County（ referred to as Ta County） from 2015 to 2023 was selected as the research object.A road network development degree and accessibility evaluation model was constructed by road space index, weighted average travel time and geographic detector, and the evolution characteristics of the spatial pattern of accessibility were analyzed to explore the main factors affecting the spatial differentiation of accessibility.The results show that: The development level of the road network in Ta County is increasing year by year, and the more developed areas are mainly concentrated in the northwest of Tashkurgan Town.The overall level of road network accessibility in Ta county is gradually improved, but there is a rule of distance attenuation along the 314 National Road, that is, the farther away from the 314 National Road, the worse the accessibility.The spatial pattern differentiation of road network accessibility in Ta County is driven by multiple factors.In general, geographical environment factors have a greater impact than that of socio-economic factors, while slope and household population play a leading role in the spatial differentiation of road Internet access.