The relationship between the normalitied difference vegetation index(NDVI)and precipita-tion is analysed, using the precipitation data in the arid and semi-arid region in the north of China. The result shows that the nonlinear relationship between cumulative NDVI (and maximumNDVI) by the end of growing season and the cumulative precipitation is significant. Its correlation coefficient is 0.78; In Huabei and Southwest China,the relationship between cumulative NDVI (and maximum NDVI) in the medium of growing season and the absolute moisture in 0-50cm soil layer is nonlinear. Its correlation coefficient is 0.60-0.65 (0.60-0.63).