Abstract: The studies on multi_functions of grassland ecosystem, carbon cycling and trace gases, long_term monitoring of climate change and its effect on grassland ecosystem, degradation and restoration processes of grassland ecosystem, sulful cycling and effect of sulful fertilizer on grazing ecosystem, and grazing ecosystem management have took a great progress at the Inner Mongolia Ecosystem Research Staton (IMGERS) since 1998. The results showed that organic carbon in soil was seriously affected by the conversion from grassland to cropland, it decreased by 34%, the soil-vegetation system was a light sink of atmospheric CH 4. the warming trend was observed at IMGERS in the recent 20 years, especially in winter. Temperature increases in the winter have aggravated the drought in spring in this region, hence the grassland productivity is decreased. Grassland degradation is grassland ecosystem degradation. The S fertilizer application could increase S concentration in grasses, productivity of communities of pasture and wool production and quality.