Lake is a geographical unit sensitive to climate change; it is an important aspect to understand the responses of terrestrial hydro-ecological process to future climate change in different regions. Especially, the lake variation is a significant indictor for ecological conservation and sustainable development in arid and semi-arid zone. Researches have indicated that lake fluctuation was influenced by climate change, but few analyzed the relationship between lake variation and climate change based on lake scale and precipitation classification. RS and GIS techniques were employed in this article to analyze the relationship between lake area/number and precipitation class in Horqin Sandy Land. Analysis showed that air temperature increase and annual precipitation reduction are two dominant characteristics in Horqin Sandy Land from 1971 to 2010. Five-year moving average analysis revealed that the annual mean air temperature had a turning point at 1990 and the mean value was (7.36±0.55)℃ from 1991 to 2010, higher than 0.52℃ of the global mean during same period. The lake area and number were changed in a pattern of parabola form 1975 to 2009, and the peaks of the both were at 1995. There was a rapid lake shrinkage in recent decade, and as a result the number and area of lakes with an area more than 0.05 km² in 2009 was less than 11% and 26% of that in 1995, respectively. Lake variation was not affected by precipitation distribution in a year, but the amount of annual precipitation. The annual mean air temperature was not a significant factor to lake variation.