Based on TM images from 1986 and 2000,an index of wetland landscape pattern was calculated using Apack software package to investigate spatial and temporal patterns of wetland change in the Dadu River catchment.Results showed that the wetland area increased 1095.79 hm2 over the last two decades,which accounted for 6.65% of the landscape area in 2000.The patch density did not change between years,convergence indices were all above 0.99,wetlands showed concentrated distributions and low fragmentation,and the diversity index and dominance index were high.There were five wetland types in this region but the landscape was dominated by marsh wetlands (> 74%).The centroid of the marsh wetland distribution moved 127.6 km to the south and 127.9 km to the southeast,but there were no changes for other wetland types.The centroid of the whole wetland landscape distribution moved 0.09o to the north and 0.01 o to the west moving approximately 9.96 km northwest.