Climate change and human activities are the main driving factors affecting the dynamic change of grassland.Understanding the impacts of climate change and human activities on the dynamic change of grassland is essential to ensure protection of grassland ecosystems.In this study,the Carnegie-Ames-Stanford approach(CASA)and the synthetic model were used to estimate actual net primary productivity(ANPP),potential net primary productivity(PNPP)determined by climatic conditions, and the difference between PNPP and ANPP attributed to human activities(HNPP)in Inner Mongolia grasslands(meadow steppe,typical steppe,and desert steppe).Quantitative analysis of the ANPP,PNPP,and HNPP was conducted to assess the dynamic change of grassland in the Inner Mongolia Autonomous Region during the period of 2000-2016to unravel the relative roles of climate change and human activities in the dynamic process of grassland change.Over this period,Inner Mongolia grasslands showed an overall trend of restoration.Area of grassland with a restoration trend was 489 334km~2,accounting for 94.2% of the total grassland area in this region.Climate change(i.e.increase in precipitation)and human activities(i.e.ecological conservation projects)were the main driving factors of grassland restoration.Area of grassland restoration attributed to climate change and its combined action with human activities accounted for 54.9%and 45.1%of the total area of grassland restoration, respectively.Unreasonable human activities(i.e.overgrazing)were the leading factors of grassland degradation.The dominant factors for grassland restoration were,however,not the same for the different grassland types.