Abstract: Based on the model of Carnegie Ames Stanford Approach(CASA),the net primary productivity (NPP)of Qilian Mountains was estimated with the data of MODIS(from NASA)and meteorological data (from China meteorological science data sharing service)from 2003 to 2013. The response of NPP to climatic factors was further analyzed with the simple correlation analysis and partial correlation analysis. Results show as follows:(1)there exist obvious annual change of Net primary productivity in Qilian Mountains,with which the growing season is concentrated on five months of a year from May to September. The average values of net primary productivity in July is above 89.96 gC·m^-2 in the east and middle of the Qilian Mountains,while only 12.10 gC·m-2 in DaChaidan Station in the west of Qilian Mountains.(2)the simple correlation analysis showed that the sensitivity of net primary productivity to the change of temperature was more obvious than that to the change of precipitation in Yeniugou,Wushaoling and Qilian,which was opposite to the phenomenon in Gangcha,Tuole, Dachaidan and Menyuan that the sensitivities of net primary productivity to the change of precipitation was more obvious than that to the change of temperature.(3)there are obvious lag effects of the responses of net primary productivity to temperature and precipitation in Qilian Mountains,and the lag stages were one month or three months,and the lag effects of net primary productivity to cumulative precipitation were differ from one month to five months.(4)the results of partial correlation analysis showed that the net primary productivity to temperature when controlling the precipitation influence in growing season was obviously correlated in Qilian,Yeniugou, Wushaoling and Gangcha,while the net primary productivity to precipitation when controlling the temperature influence was obviously correlated in Gangcha,Yeniugou and Tuole,of which the correlation degrees were the same with those of the simple correlation analysis.

Key words: net primary productivity, correlation analysis, lag effect, cumulative lag, Qilian Mountains