With actual historical data and climate monitoring data,reasons for sharp reduction of Qixinghe wetland area were studied by analyzing the administrative region changes,land use and climate change arround the Qixinghe wetland. The results show that, the south of wetland area is reducing constantly with the ploughland of Baoqing County close to the wetland extending to the north. From 1957 on, the wetland area has decreased 16156 hm~2, which is 45% of the wetland area in 1957. The direct and most important reasons for the sharp reduction of the wetland area are the increase of population and the farming of wetland. Climate changes, such as decrease of precipitation, sharp reduction of runoff, increase of cut-off days etc.,also has some adverse influence on the water resource system of the wetland,and at the same time,climate warning significantly decreases cold damage and increases the active accumulative temperature,which is beneficial to the increase of grain crops yield of the surrounding administrative regions of the wetland.