Context: Understanding changes in agroecosystem net primary productivity (NPP) and human appropriation of NPP (HANPP) is critical for climate change mitigation and food security. However, such knowledge remains limited in arid regions, where agroecosystems are subjected to different levels of drought stress. Objective: This study evaluated changes in agroecosystem NPP and HANPP under different drought stresses and explored their underlying mechanisms in Western Jilin Province, China, from 2010 to 2020. Methods: Crop type, irrigation data, multisource remote sensing data, and the Carnegie-Ames-Stanford Approach model were integrated to estimate changes in NPP and HANPP. Two scenarios were then designed to separate the effects of climate change and land use/land cover change (LUCC) on NPP, and the responses of NPP and HANPP under different crop types and drought stresses were compared. A structural equation model was used to explore the underlying mechanisms of NPP and HANPP changes under different drought stresses. Results: From 2010-2020, regional mean NPP increased from 159.29 to 180.30 gC/m2, with greater increases in low-than in high-aridity index (AI) regions. Climate change reduced NPP by 9.06 gC/m2, whereas LUCC increased it by 34.41 gC/m2; the negative climate effect strengthened and the positive LUCC effect weakened with increasing AI. Rice HANPP and HANPPluc increased by 89.04 and 93.93 gC/m2, respectively, whereas those of maize and soy decreased. In contrast, rice HANPPhar decreased by 4.32 gC/m2, whereas maize and soy HANPPhar increased by 13.26 and 15.64 gC/m2, respectively. Conclusions: Climate change mainly had a negative impact on NPP change but a positive impact on HANPP change, and the effect of LUCC was the opposite. As drought increased, the impact of climate change on NPP and HANPP shifted from temperature-and energy-limited to water-limited. Implications: Increased crop yields and use efficiency require improved crop management and irrigation. This study can provide effective guidance for sustainable agroecosystem management and ensuring food security under drought stress.