Taking Lake Taihu which was the third largest shallow lake in China as an example, we researched the demarcation of buffer zone on the basis of information collection, topographic survey and field investigation.On domestic and international litera-tures about buffer zones of lakes, we preliminarily defined approximately 2 km wide as the width of Lake Taihu buffer zone.Con-sidering the principles of land markers (villages, roads, mountains)and regional differences of regulations and planning, we de-fined the upper and lower boundaries of the buffer zone.The lower boundary was at the lake shoreline or levees around the lake.The upper boundary was at approximately 2 km from the lower boundary.According to land use types, there were three typical types of villages, roads and mountains in Lake Taihu buffer zone.The upper boundary at village area was divided by the adminis-trative villages about 2.0 km from the lakeshore, and was divided by roads when the roads are paralleled with the lake shores.At mountain area, the upper boundary was divided by mountain ridges.On the 1∶ 5000 topographic maps, we calculated 382.75 km in total length and 452.31 km² in the total area of Lake Taihu buffer zone by means of Auto CAD software.