Abstract：Accurately assessing the spatiotemporal dynamics of vegetation net primary productivity (NPP) in sandy ecosystems and quantifying the respective roles of climate change and human activities are crucial for elucidating the impacts of environmental change on the carbon pool in sandy ecosystems and for developing strategies to enhance carbon sinks. Based on MOD17A3HGF data products, we systematically analyzed the spatiotemporal patterns of vegetation NPP and their driving mechanisms in the Horqin region from 2001 to 2023, employing a combination of trend analysis, stability analysis, partial correlation analysis, and partial derivatives. The results indicated that: ① From 2001 to 2023, the vegetation net primary productivity in the Horqin region exhibited a spatial pattern of being higher in the northwest and southeast and lower in the central region, with a significant increase at a rate of 4.78 g C/(m² ⋅a). An impressive 89.3% of the region experienced significant recovery, with 72.6% maintaining stable condition. The recovery rate of net primary productivity was stronger in fixed sands than that in mobile sands. ② The climatic conditions in the Horqin region were characterized by a warming and humidification trend. The magnitude of climate changes was generally higher in desertified areas than in non-desertified ones. ③ Vegetation net primary productivity showed positive correlations with annual precipitation, and annual mean temperature, but was negatively correlated with annual mean solar radiation, with precipitation dominating the variation in vegetation net primary productivity. ④ In vegetation restoration areas, regions where net primary productivity changes were jointly driven by climate change and human activities, and those primarily driven by human activity accounted for 82.2% and 16.6%, respectively. However, in areas of vegetation degradation, the dominant influence of human activity remains non-negligible. Net primary productivity in mobile sand areas was predominantly influenced by climate change, whereas in fixed sand areas, it was substantially affected by anthropogenic activities. Our findings robustly endorse the following management strategies that facilitate the natural restoration of mobile sands by adapting to the prevailing trends of climate warming and humidification and enhancing the carbon sequestration and carbon sink capacity of sands through the regulation of agricultural practices. These insights provide a scientific foundation for targeted implementation of desertification control and ecological restoration efforts in the Horqin region.