Abstract: This paper is based on the meteorological observation data of the five meteorological stations(Shiquanhe,Gerze, Xianza,Bangoin and Amdo)near Qiangtang National Nature Reserve, the climate of Qiangtang National Nature Reserve from 1960 to 1990 and the estimated grid data in the future issued by IPCC5. The Miami model, Thornthwaite Memorial model, and tendency rate were used. The statistical analysis methods were used to study the spatiotemporal evolution of Net Primary Productivity in Qiangtang National Nature Reserve and its response to climate change. The results showed that: (1) the average annual temperature decreases from the west to the east, and the annual precipitation increases from the west to the east. The annual mean temperature(T) showed a significant increasing trend, while the annual precipitation(R) and annual evapotranspiration(E) showed a slight increasing trend. NPP of Temperature(NPPt) and NPP of precipitation(NPPr) showed a slight increasing trend at all stations, and NPP of evapotranspiration(NPPe) and standard NPP(NPPb) showed a slight increasing trend at most stations. (2) NPPt gradually decreased from the west to the east, NPPr gradually increased from the west to the east, NPPe and NPPb first increased and then decreased from the west to the east. The limiting factor of NPP was precipitation in Shiquanhe station and Gerze station, evapotranspiration in Xianza station and Bangoin station, and evapotranspiration or air temperature in Amdo station. (3) The NPPt, NPPr, NPPe and NPPb in different periods of the 21st century were significantly higher than those in all periods of the 20th century. The NPPt, NPPr, NPPe and NPPb were significantly increased in the future under different emission scenarios compared with those from 1960 to 1990. Under the trend of "warming and wetness" in the past 48 years and in the future, the NPP of vegetation increased, and the increase was larger in the cold and humid area in the southeast, but less in the cold and arid area in the northwest. The future climate is conducive to the improvement of local vegetation NPP and the improvement of local ecological environment. Assessing the possible impact of future climate change on the ecological environment of Qiangtang Plateau. The results not only provide a basic method for studying the Net Primary Productivity of vegetation in no man's land at regional scale, but also have important reference value for estimating ecological security research and ecological function planning.

Key words: Climate change, Net primary productivity(NPP), Miami model, Thornthwaite memorial model, Qiangtang National Nature Reserve