The Yellow River Basin is in an important strategic position of ecological protection and construction in China, but the ecological environment of the basin is fragile. Especially under the influence of human activities and climate changes, the ecological characteristics of the Yellow River Basin have gradually changed, and ecological security is facing major challenges. In order to understand the impact of extreme climate change on ecological quality of vegetation in time, the vegetation ecological quality index (EQI) was constructed by net primary productivity (NPP) and fractional vegetation cover (FVC) as the evaluation index. By using MODIS and meteorological data from 2000 to 2020, this paper estimated the EQI and extreme climate indices in the Yellow River Basin. Based on the EQI and extreme climate indices, the aims of the present study analyzed the temporal and spatial variation characteristics of the EQI in the Yellow River Basin, and discussed the response characteristics of EQI to extreme temperature indices and extreme precipitation indices during 2000-2020, using methods of linear regression, the Hurst index, correlation analysis and other methods. The results showed that:(1) in the seasonal and annual scales, the EQI in the Yellow River Basin showed a volatility increasing trend from 2000 to 2020, which was the highest change rate of 6.7/10a in the summer. (2) In the trend analysis of EQI change, the area of increasing trend accounted for 97.7% of the basin area, of which 37.4% showed an increasing trend with the change rate >5/10a. The Hurst index of EQI in the past 21 years was 0.8, which indicated that the EQI would maintain the same trend of change in the future. (3) The EQI was negatively correlated with the extreme temperature indices, of which the correlation coefficients were mostly between -0.3 and 0.3. Among which, the number of observation stations with positive correlation between EQI and number of frost days (FD0) and number of summer days (SU25) was the largest, accounting for 78% of the total. (4) The EQI was positively correlated with the extreme precipitation indices, of which was higher than temperature indices. With positive correlation, the number of observation stations accounted for 78% of the total, which the percentage of stations that reached a significant level was 37% on average. (5) Since 2000, the variation of precipitation and temperature in the Yellow River Basin has fluctuated greatly, but generally showed an increasing trend with 31.8 mm and 0.33℃ per 10 years. Warmer and wetter climate during 2000-2020 was the main driving force to promote vegetation EQI in the Yellow River Basin, which indicated that precipitation might be the key influencing factor for the vegetation EQI.