Abstract: The Net Ecosystem Productivity (NEP) in the Kekeya greening project area, Xinjiang from 2000 to 2020 was estimated by using the Boreal Ecosystem Productivity Simulator model and the relative impacts of climatic factors and human activities on NEP changes were explored. The results showed the following: 1) The annual average NEP in the Kekeya, Xinjiang greening project area from 2000 to 2020 ranged from 61.67 g(C) m⁻² to 154.99 g(C) m⁻², exhibiting spatial differences characterized by higher values in the west and south and lower values in the east and north. 2) Annual NEP showed a significant fluctuating upward trend (P ＜ 0.05), with an increase of 5.12 g(C) m⁻². The regions with larger increases in NEP were mainly concentrated in the northwestern and southwestern parts of the Kekeya greening project area, while the southern and eastern regions showed smaller increases. 3) The correlation between NEP and temperature (precipitation) was weak in the Kekeya greening project area, with only about 0.99% (0.60%) of the regions passing the significance test of P ＜0.05 for the correlation between NEP and temperature (precipitation). 4) Compared with climatic factors, human activities were the dominant factor influencing changes in NEP in the Kekeya greening project area, with about 96.87% of the regions showing a contribution of more than 90% from human activities.