Abstract: [Objective]To explore the response mechanism of vegetation to drought, identify the temporal and spatial evolution characteristics of drought and its negative impact on vegetation NPP.[Method]Drought characteristics was quantified by Standardized Precipitation Evapotranspiration Index (SPEI) , and NPPwas estimated based on MODIS remote sensing data by Carnegie-Ames-Stanford Approach (CASA) model and annual SPEI index during 2001 to 2020 in the middle arid zone of Ningxia was calculated to explore the response characteristics and differences of NPP of different vegetation types to SPEI, and the correlation between NPP loss due to drought(?NPP) and SPEI index by using the methods of trend analysis, Mann-Kendall test and correlation analysis. [Result]The results showed that: (1) during 2001 to 2020, the SPEI index indicated that the drought trend in the study area was generally slowing down , drought was still dominant on spatial scale, but there was a trend of humidification. (2) ?NPPin the study area showed a totally decreasing trend of fluctuation; spatially, the ?NPP in the eastern part of the study area decreased significantly. (3) The correlation analysis between SPEI index and ?NPP showed that the positive correlation was dominant, but there were obvious spatial-temporal differences due to different drought grades. (4) The response of ?NPP of different vegetation types to annual SPEI was different , under severe and extreme drought stresses, the NPP loss of forest was the largest, followed by crop, and shrubs was the least. [Conclusion]In general, drought was the main factor restricting the growth of NPP in the study area. In order to improve the resistance of vegetation to drought in the study area, the complexity and diversity of vegetation structure and composition should be improved.