Abstract: This paper investigated the change of area of the Mapangyong Co Lake and Laang Co Lake in Pulan County, Tibet Autonomous Region and its response to climate change based on the topographic map in 1975, TM satellite remote sensing data in the years of 1990, 1999-2009 and climatic data including air temperature, precipitation, snowcover days, evaporation, etc. in recent 35 years (1975-2009). Results indicate that the areas of both the Mapangyong Co Lake and Laang Co Lake were reduced at first and then enlarged. Holistically, the areas of these two lakes were in a reduction. Areas of the Mapangyong Co Lake and Laang Co Lake were reduced to 415.44 km² and 261.36 km² in 2009, and they were reduced by 1.56 km² and 11.01 km^2, respectively. Furthermore, the areas of modern glaciers near the lakes were also reduced due to climate warming. According to the statistical results of meteorological data in Pulan County during the period of 1975-2009, the decrease of precipitation was the dominant factor resulting in the reduction of lake areas, and then the slight increase of evaporation and the melt of modern glaciers.

Key words: Mapangyong Co Lake, Laang Co Lake, lake area, climate change, Tibet