Abstract: Due to the natural geographical location,economic and other reasons,the traffic of Qinghai Province,China is relatively backward,the highway has been located at a very important position in the transportation network of Qinghai Province in the long time.This paper takes 1986,1995,2004 and 2016 as the time section,obtains Qinghai Province highway traffic network data based on Arcgis spatial analysis module,and analyzes the accessibility and evolution of the 43 main points in the cities of Qinghai Province highway network using the weighted average travel time method,the spatial pattern of Kriging interpolation method.As a whole,the level of accessibility in the spatial distribution shows a decreasing trend from Xining City and Haidong City to other parts of the province,and the contour accessibility line presents a semi annular irregular distribution.The accessibility of Xining City and Haidong City is the best during the study period,especially it is the highest in Xining City.The main factors impacting the accessibility include the geographical location,traffic conditions,urban economic and so on.The accessibility interpolation shows the directivity of traffic trunk road.Accessibility dynamic evolution shows that the road network accessibility levels of the 43 nodes have been increased in Qinghai Province and the variation of accessibility represents concomitant characteristics of similarities and differences.The spatial distribution of the contour accessibility line variation ratio shows trunk road directivity, such as the national highway and the motorway.The similarity shows a declining trend from the northeast to the west and the south region of the province.But there were differences in the level of the accessibility in three research stages.During 1986-2016,the economic linkage intensity and economy linkage volume among the counties in Qinghai Province has shown a growing trend,especially the total volume of economy linkage grows faster and faster.The economic linkage intensity of the top five and the economy linkage volume of the top three mainly concentrate in Xining and Haidong City.It reflects the typical "single core" urban spatial structure of Qinghai Province,and the radiation and leading effect of the provincial administrative center is very obvious.There is a positive correlation between the accessibility and economic linkage intensity or volume in the region.

Key words: accessibility, economic linkage, spatial pattern, Qinghai Province