The climate in the Qinghai-Xizang plateau has been becoming warmer since the late 1970' s ,that have resulted in a regional permafrost degradation in the plateau.The mean annual ground temperatures rose 0.1～0.5℃,uncoincidently frozen ground and residual thawed layers in the vertical profile have been forming in the fringe,the lower limit of permafrost distribution rose about 40～80 m,and the total area of permafrost has been disminished 10×104km2.