Abstract.The wetlands dynamics was investigated in Nansi Lake for the period between 1987 and 2007. Four periods of remote sensing images, including TM&ETM and SPOT images, were used to locate and quantify the changes. Results show that from 1987 to 2007 the reclamation in Nansi Lake was serious. A large part of the lake had been replaced by land, the open water region only accounted for 51.3 percent. Farmland was distributed along the coast of lake accounting for 13.3 percent. Aquaculture ponds area was 37430 hm2，accounting for 29.7 percent. Comparing the three time period (1987-1991, 1991-1999 and 1999-2007), more changes in the cover areas occurred during the period 1991-1999 and 1999-2007 which is characterized by human interventions.