Abstract: Combined the three ladder distribution of China,authors analyzed the spatio temporal variations of vegetation NDVI and its responses to the variations of temperature and precipitation in month scale,based on the GIMMS NDVI datasets and month temperature and precipitation data from meteorological stations in Yangtze river basin during 1982 to 2006.The results showed that there were significant spatial differences of Yangtze river basin vegetation.The significant increased area was accounted for 18.22%,which mainly distributed in the first step and the second step,while the significant decreased area was accounted for 8.72% and mainly distributed in the second and third step.Analyzed on the time,found that the response of NDVI to the variation of temperature was greater than to that of precipitation,the maximum response of NDVI to temperature changing without delay,while the maximum response of precipitation delayed one month,spring vegetation was responded most to temperature and fall vegetation was responded most to precipitation,the lag time of summer vegetation responded to temperature and precipitation was longer than other seasons.Analyzed on the space,found that the most significant response of vegetation to temperature and precipitation was occurred in the first step,and the longest lag time respectively occurred in the first step and the third stepMoreover,because of the effect of mountain barrier,the area from the first step to the second step and the second step to the third step,the maximum response of vegetation NDVI to the variation of temperature and precipitation of higher place was significantly greater than that of lower place.

Key words: GIMMS NDVI, Climatic change, Temperature, Precipitation, Yangtze river basin