Abstract: Vegetation coverage is an important indicator of land ecology. The Yellow River Basin is an important national ecological barrier. It is also an important economic zone and energy basin. In order to reveal the changes in the ecological environment of the Yellow River Basin, based on the GIMMS NDVI data, land use data, topographic data and climate data and Mann Kendall, Sen method and geographical detectors, this paper explores the spatio-temporal dynamics of seasonal NDVI in the Yellow River Basin in recent 40 years and the contribution of different factors to seasonal NDVI changes. The results show that（1） the NDVI value in arid areas was the lowest, the second was the semi-arid area, the humid area had the highest NDVI and the second was the semi-humid area.（2） The increase rate of NDVI in spring was 0.001 2/a. The NDVI change in 2005 was abrupt. The increase rate of NDVI in summer was 0.001 4/a. 2008 was the year of NDVI mutation. The increase rate of NDVI in autumn was 0.001 5/a. The year 2002 was the mutation year of NDVI in autumn. The increase rate of NDVI in winter was 0.000 4/a. 2007 was the year of NDVI mutation.（3） The increase rate of NDVI decreased with the increase in altitude, especially in summer. The slope had little effect on the change rate of NDVI in spring and winter, but the change rate of NDVI in summer and autumn decreased significantly with the increase in slope.（4）The q influence of different factors on NDVI was the q determinant of the minimum value of daily maximum temperature（TXN） ＞ the maximum value of daily minimum temperature（TNX） ＞ the minimum value of daily minimum temperature（TNN） ＞ average annual temperature（TEM） ＞ land use（LUCC） ＞ the maximum value of daily minimum temperature（TXX） ＞the maximum value of rainfall for five consecutive days each year（RX5DAY） ＞ wind speed（WIN） ＞ altitude（DEM） ＞SLOPE＞ average annual cumulative precipitation（PER）. The interaction of any two factors was more than or equal to the effect of a single factor on NDVI. The q determinants of TEM and per on NDVI decreased with time, while the q determinants of LUCC and SLOPE increased. Extreme temperature and precipitation have no obvious time trend.