The levels and the surface areas of lakes are indicators of the climate change and the climate variability. In order to assess the surface area variations of lakes in the Tibetan Plateau and their influencing factors, the surface extent of all lakes in the Tibetan Plateau is extracted from the Landsat remote sensing images of the 1970's, the 1990's, around 2000 and 2010, to develop the lake spatial database based on the RS and GIS technologies. Moreover, the annual average temperature and the annual precipitation from 1961 to 2010 at 47 weather stations are collected. It is shown that the number and the total surface area of the lakes in the Tibetan Plateau increase significantly from 1973 to 2010. The surface area variations of the lakes are mainly influenced by the increasing temperature and precipitation, as well as the decreasing evaporation. Additionally, there are other factors responsible for the changes, i.e., the glaciers, the human activities, the lake basin shape, and the recharge and discharge areas.