Net ecosystem productivity (NEP) is an important indicator to quantitatively describe the carbon exchange between terrestrial ecosystems and the atmosphere. Clarifying the temporal and spatial patterns of NEP at the regional scale and its dominant factors is helpful to enhance the understanding of the mechanism of regional carbon cycling. Based on the simulation of BEPS model, this paper evaluated the spatio-temporal pattern of NEP in Anhui Province from 1982 to 2020, analyzed the sensitivity of NEP to major environmental and vegetation factors, and explored the driving factors affecting the spatio-temporal change of NEP with the help of path analysis and contribution analysis. The results showed that:(1) the annual average NEP in Anhui Province was 651.14 gC/m², and NEP overall showed a significant increasing trend with the linear trend change rate of 1.10 gC m^-2 a^-1 (P<0.01) from 1982 to 2020. Spatially, NEP showed the distribution of "higher in the north and south and lower in the middle". The areas with significant increase accounted for 52.77% (P<0.05), mainly in the north and south regions, while the areas with significant decrease accounted for 7.11% (P<0.05), mainly in the west and southeast regions. The center of gravity of NEP had a significant northward shift trend (P<0.01). (2) NEP was the most sensitive to changes in atmospheric CO₂ concentration and the least sensitive to changes in precipitation. In terms of time, the sensitivity changes of NEP to leaf area index (LAI) (P<0.01), CO₂(P<0.01), and vapor pressure deficit (VPD) (P<0.05) were significantly enhanced, but the sensitivity change to total radiation (Rad) was significantly weakened (P<0.01) and the sensitivity change to air temperature and precipitation did not change significantly (P>0.05). The sensitivity of NEP to each factor varied with region on the spatial scale. (3) The selected environment and vegetation factors comprehensively explained 79% of the temporal and spatial variations of NEP. LAI and CO₂ were the dominant factors of NEP variations, and showed the positive contributions to NEP changes, while climate factors had negative contributions to NEP changes. LAI and CO₂ were the dominant factors of spatio-temporal variation of NEP in Anhui Province, with positive contributions, while climate factors as the secondary dominant factors had negative contributions. Spatially, the LAI as the dominant factor determined NEP changes in 49.65% of the Province that mainly distributed in northern, central and western Anhui province; CO₂ as the dominant factor played a leading role in 44.54% of the Province that mainly distributed in northwest and southeast Anhui Province.