Based on 505 scenes of Landsat images, the distributions and variations of the glacial lakes within Chinese territory were investigated by combining automated glacial lake boundary extraction and artificial visual interpretation in 2000 and 2020. Compared with the glacial lake inventory data in 1990, the characteristics and affecting factors of the glacial lake changes in China during the period of 1990-2020 were analyzed. The results showed that the glacial lake area in China increased by (180.1±0.1) km² from 1990 to 2020, with a change of 17.9%. Thereinto, the glacier-fed lake area expanded significantly, with the area expansion of 22.9%, while the non-glacier-fed lake area changed only 4.9%. The glacial lake area showed a rapid growth trend at high altitude during 1990-2020. During this period, the glacial lake area expanded the most at above 5500 m, reaching 30.5%. At the subregional scale, precipitation and evaporation mainly affect the changes of non-glacier-fed lakes, where evaporation played a more significant role. Temperature rise and glacier retreat are the main reasons for rapid expansion of glacier-fed lakes.