As forcing factors of land surface,the snow cover and frozen soil play important roles in the climate system.Based on the monthly snow cover days of 81 meteorological stations and the observation data of the lower boundary of the first frozen layer of 45 stations in the Tibetan Plateau from 1971 to 2016,the temporal and spatial variation characteristics of snow cover and frozen soil in the Tibetan Plateau and their relationships with NDVI (Normalized Difference Vegetation Index) were analyzed.The possible influence of changes in the underlying surface of snow cover and frozen soil on the vegetation and desertification in the Tibetan Plateau were also discussed.Results show that:(1)The distribution of snow cover days in the Tibetan Plateau is extremely uneven.The Bayan Har and Tanggula mountains are high value areas of snow cover days in the plateau,and their interannual variabilities are large.(2)There is a decreasing trend of snow cover days in the Tibetan Plateau from 1971 to 2016,and the average reduction rate is 3.5 d/(10 a).A sudden change of the snow cover days occurs around 1998,and the reduction rate is further accelerated to 5.1 d/(10 a).(3)The lower boundary of the first frozen layer in the Tibetan Plateau from 1971 to 2016 shows an upward trend,reaching -3.7 cm/(10 a),which is closely related to the warming of the Tibetan Plateau.(4)NDVI in the Tibetan Plateau is increasing slowly,which is consistent with the increasing trend of temperature and precipitation.The effect of snow cover and frozen soil changes on NDVI in different regions of the Tibetan Plateau has significant difference.Under the background of climate warming,the warm and humid environment promotes the melting of snow and the lifting of the lower boundary of the first frozen layer.Further,the water content of shallow soil layers increases,which is conductive to vegetation restoration and growth.The results have a certain role in the study of land desertification on the Tibetan Plateau.