To reveal the evolution characteristics and driving factors of net primary productivity (NPP) of vegetation in arid regions, with Kashi region as a representative case, this study utilized various remote sensing satellite data, including MOD13A1/Q1, MOD09A1, and MOD17A3, to estimate vegetation NPP in the study area from 2001 to 2020 using the CASA model. The study aimed to express the impact of external driving factors on vegetation NPP from the perspectives of climate change and land use change. The results indicated: (1) Over the past two decades, the overall trend of vegetation NPP in the study area exhibited an initial increase, followed by a subsequent decrease. Specifically, from 2001 to 2015, vegetation NPP increased at a rate of 0.303, while from 2016 to 2020, it decreased at a rate of -0.202. (2) Through trend analysis and significance testing using the Sen+MK method, it was found that 37% of the study area showed a significant increasing trend in NPP, while 73% exhibited a decreasing trend. (3) Precipitation in the Kashi region had a stronger correlation with NPP than temperature. In the southwest region, the Pamir Plateau and Karakoram Mountains showed positive correlations with both temperature and precipitation, with warm and moist airflows promoting NPP in high latitudes. (4) )During the period of 2001-2020, Grassland in the study area degraded at the fastest rate, with a change rate of -2.1%, and the largest increase was observed in farmland, with a change rate of 2.7%; the vegetation NPP decreased by a total of 2748.3 TgC , and the study area shows a decreasing trend in the value of vegetation NPP in the future period.