Abstract:The temperature variations are the hot issues in freeze soil mechanics. After roadbed being built in permafrost regions,there will be dissimilar thermal regime on slopes because of different roadbed orientations,which will lead to distinct thawing morphologies under the embankment. In view of the specific natural environment of Qinghai—Tibet Plateau,field monitored ground temperature and meteorological data are difficult to obtain,therefore a regression equation by statistics method between the temperature difference of shallow ground(0.5m) and solar radiation difference on slopes is adopted,and the equation is validated,which can better disclose the mean annual temperature difference on slopes of railway roadbed along different routes in Beiluhe. The equation may provide the dependable science basis for the road construction and maintenance on permafrost regions of plateau.