Abstract: Changes of the Normalized Difference Vegetation Index(NDVI) of four main vegetations including crop,grass,forest and shrub in the Yellow River Basin and their relationship with the precipitation,temperature and Availability of Precipitation Index(API) were analyzed,by using NOAA and climate data from 1982 to 1999.The results showed that NDVI increased during 1982 to 1999 which indicated an improved ecological system.The NDVI in June was positively correlated to contemporaneous precipitation.There existed a positive lag correlation between precipitation in July and NDVI in August for crop and grass.The NDVI in August was sensitive to precipitation in the previous month.The NDVI was positively correlated to contemporaneous temperature,but negatively to contemporaneous API during spring,which indicated that higher temperature during spring benefited to plant growing.

Key words: Yellow River Basin, Yellow River Basin, NDVI, Precipitation, Temperature, API