Abstract: Net Primary Productivity (NPP) of vegetation is a critical component of the terrestrial carbon cycle, and plays an important rolein global climate change and carbon equilibrium. Based on the CASA model, this study calculated and compared the spatial variations and key controlling factors of NPP in the Heihe River Basin, Weihe River Basin, and the lower reach of Yangtze River Basin from 2010 to 2019. These three basins represented the arid, semi-arid and humid zones, respectively. Results indicated that:(1) The NPP value and its increasing rate in the lower reach of Yangtze River Basin wereobviously higher than those in the Heihe River Basin and Weihe River Basin.(2)The area proportions and areal mean NPP values of different land cover types were the dominant factors determining the spatial patterns of NPP in the three basins. Grassland and the unutilized land had the greatest contributions to the NPP in the Heihe River Basin, while grassland and farmland contributed the most to the total NPP in both the Weihe River Basin and the lower reach of Yangtze River Basin. (3) The spatial patterns of NPP in different basins variedaccording to thespatial patterns of elevation and slope. However, similar increasing and then decreasing trend of the NPP with the increasing of annual mean temperature and precipitation were also observed in these three basins.(4) The NPP in the Weihe River Basin was primarily influenced by the meteorological factors, while that in the lower reach of Yangtze River Basin was strongly influenced by the terrain factors, and in the Heihe River Basin, the meteorological and terrain factors had similar effects on the NPP. These results are of significant importance for identifying the main controlling factors of vegetation NPP changes in different climatic regions and for estimating  the carbon sequestration potential of terrestrial ecosystems.