Abstract: With the support of the remote sensing（RS） and geographical information system（GIS） techniques， land use change information was extracted by taking the Landsat TM／ETM+images of Wuxi city as the data source. The dynamic degree method was utilized to analyze the integrated rate of land use change, and according to the land use transition matrix， we digged hidden information about the net change， swap， persistence of changes， etc. Systematic transitions and random transitions were used to determine intensity of different class switch， which intend to discuss its effects on ecological environment around Taihu Lake basin. The research results showed that during 1991—2006， the area of construction land in Wuxi city grew rapidly， accompanied with high loss rate of forestland； the amount of net change for construction land was the largest， and the change in cropland was nearly a pure swaptype of change； according to excepted gains and excepted losses， there was an obvious advantage for the forestland to transform into cropland. Meanwhile， part of the cropland were turning back to forestland. It should be considered that spatial location conversion varied intensely between forestland and cropland， which might aggravated forestland landscape fragmentation. It is beneficial for the control of nonpoint pollution from cropland and the improvement of lake water quality to protect the present forestlands and establish vegetation buffer zones surrounding Taihu Lake.