Measuring the impacts of anthropogenic activities on grassland ecosystems is of great significance to establish effective grassland management policies. Due to the uncertainty and complexity of the anthropogenic activities, the impacts are difficult to quantify, especially at large spatial and long temporal scales. We used the Zhou Guangsheng model to simulate climate‐driven potential net primary productivity (NPPP) and MOD17A3 NPP data to acquire actual NPP (NPPA) influenced by both anthropogenic activities and climate change over the temperate grassland of Inner Mongolian from 2000 to 2014. We then simulated human‐induced NPP (NPPH), calculated as the difference between actual and potential NPP (NPPH = NPPA − NPPP), to determine anthropogenic effects on the temperate grassland. By comparing the NPPH and its time‐series linear slope from 2000 to 2014, we further proposed six types of anthropogenic impacts. Along the temperate grassland climate gradient, vegetation changed from meadow steppe in the east to typical steppe in the middle and desert steppe in the west, and NPPA and NPPP decreased. NPPH had no obvious spatial pattern. We observed positive effect (NPPH > 0) on only 4.2% of total grassland area. The area where the types of “positive effect (NPPH > 0) decrease – negative effect (NPPH < 0) increase” and “negative effect (NPPH < 0) increase” were observed in time‐series trends accounted for 68.8% of total grassland area. The grazing withdrawal and ecological compensation programs implemented around 2004 did not lead to a decline in the number of livestock and NPPH. Governments need to improve livestock number controls and strengthen grazing regulations.