Abstract: By using RS and GIS techniques, the spatiotemporal changes of wetlands in Hangzhou Bay Industrial Belt, one of the most developed zones in Zhejiang Pr ovince, from 1990 to 2005 were studied. There was a frequent conversion between the wetlands and other land use types and between the wetlands themselves, mainl y manifested in the conversion between wetland and farmland, and from wetland to construction land and from tidal flat to aquiculture area. The comparative adva ntage of other land use types and the policy of cultivated land’s requisition- compensation balance decided the inherent mechanisms of these spatiotemporal cha nges. Driven by the aquaculture’s comparative advantage to traditional agricult ure, large areas of inland farmland and of the tidal flat along the coast of Han gzhou Bay were reclaimed into aquiculture area, and the rapid expansion of const ruction land, limited land resources, and the implement of cultivated land’s re quisition-compensation balance policy induced the wetlands being occupied.

Key words: landscape pattern, land cover, soil erosion, landscape leakiness index.