In order to monitor the wetland of the Poyang Lake national nature reserve zone, we selected three different seasons TM image data which were achieved individually in April 23th in 1988, Nov 2nd in 1994, and Jan 1st in 2000. Based on the band 5, band 4 and band 3of TM image, we divided the land coverage of Poyang Lake national nature reserve zone into three classes--water field, meadow field and the other land use by rule of maximum likelihood. Using the outcome data to make the statistical analysis, combining with the GIS overlay function operation, the land coverage changes of the Poyang Lake national nature reserve zone can be achieved. Clipped by the Poyang Lake national nature reserve zone boundary, the land coverage changes of Poyang Lake national nature reserve zone in three different years can be attained. Compared with the different wetland coverage data in year of 1988, 1994, 2000, the Poyang Lake national nature reserve zone eco-environment can be inferred from it. After analyzing the land coverage changes data, we draw the conclusion that the effort of Poyang Lake national nature reserve administration bureaucracy has worked well in certain sense.