Abstract: According to the TM satellite remote sensing data of 1989, 2000-2002, 2007, 2009, and the meteorological data from 1989 to 2009, the article concludes that :nearly 20 years, the area of DuoqingCo lake presents reducing trend significantly, the area of DuoqingCo lake reduced 28.4km2 in 20 years.And, the average annual temperature occurs significant rising trend, the annual precipitation present reducing trend.Annual precipitation reducing and temperature rising accelerates the ice melting, leads to the lack of the lake water supply, which is the main reason of the reduction of the area of DuoqingCo lake.