The daily snow cover data from 232 meteorological stations to the west of 105°E in China for the period 1951-2004 were used to classify the snow cover and analyze decadal variations of snow cover types in western China,and comparison was made between the observational data and those retrieved from passive microwave remote sensing data (SMMR and SSM/I) in 1980-2004.The results show that stable snow-covered areas included northern Xinjiang,the Tianshan Mountains,and the eastern Tibetan Plateau with more than 60 snow cover days; no snow cover was found in the center of the southern Xinjiang Basin,the Sichuan Basin,and southern Yunnan.In addition to the above-mentioned,there were unstable snow-covered areas in western China.Furthermore,the snow cover types in northern Xinjiang,the Tianshan Mountains,the Hexi Corridor,and the vast areas from Chengdu to Kunming were unchanged.In the 1980s,the south-north dividing line between the major snow-covered area and snow-free area advanced to its most southern position.The snow cover days calculated from satellite remote sensing were generally longer than those from observational data in western China,mainly in the higher-altitude mountains,the Hexi Corridor,and the western Sichuan Plateau.