Abstract: In order to explore the multiple factors affecting the change of NDVI vegetation cover, the MODIS13Q1 data set was selected to synthesize the annual, quarterly, and monthly average values of NDVI in Yunnan Province for 13 years, and the annual average value of NDVI passed the stability test of the coefficient of variation CV. From 2006 to 2018, the annual average value of NDVI in Yunnan Province was 0.641, and the average annual growth rate was 0.002 26/10 years; among the NDVI values of the four seasons, only the summer showed a negative correlation trend, and the fluctuation range was obvious. Among the monthly average values of NDVI in 13a, NDVI reached the lowest in June and July. The results of the analysis of NDVI, DEM and meteorological factors showed that the proportion of NDVI was the largest at <3 000 m, which is 91.51%, and the vegetation coverage in this area was the best; the proportion of NDVI was the largest in the 10°~15° region, and with the increase of slope, NDVI first increases and then decreases. The proportion of NDVI was the largest in the north slope, and the proportion of other slopes was basically the same, and the vegetation growth state was good. The correlation between NDVI and air temperature was better in altitude, and NDVI was mainly affected by precipitation in terms of slope and aspect.

Key words: Yunnan Province, NDVI, DEM, correlation analysis