[Objective] Conducting research on lake area changes on the Inner Mongolia Plateau is of great significance for deep understanding of regional water resource changes. [Methods] The Google Earth Engine （GEE）platform and Landsat image data were used to obtain annual lake area data on the Inner Mongolia Plateau from 1988 to 2021，and methods such as trend testing and hierarchical segmentation were used to analyze the spatiotemporal change characteristics of lakes and their influencing factors. [Results] 1）From 1988 to 2021，the area and number of lakes in Inner Mongolia showed a trend of first reduction and then recovery. On an inter-annual scale，the lake area was the largest in 2021，reaching 4 363.63 km²，and the smallest in 2002，only 1 915.61 km². In terms of the number of lakes，the number of lakes larger than 1 km² increased from 71 in 2002 to 458 in 2021. 2）Between 2012 and 2021，the area of lakes on the Inner Mongolia Plateau gradually recovered，and mainly concentrated in Alxa League，Xing’an League and Hulunbuir City. 3）The changes in lake area on the Inner Mongolia Plateau were mainly affected by climate change and human activities. From 1988 to 2012，human activities were the main driving force of lake area changes，and lake area was significantly positively correlated with precipitation. There was a significant negative correlation between lake area and irrigation，grazing and coal production. After 2012，climate factors were the main factors affecting changes in lake area. [Conclusion] The results elucidate the relationship between lake area changes，climate and human activities on the Inner Mongolia Plateau，and provide a scientific basis for ecological protection and restoration of plateau lakes.