Abstract: The grassland ecosystem plays a very important role in the global carbon cycle. But the measured data is very lacking. In this paper,based on the ground survey data of the grassland in 2008 and satellite remote sensing data in Sichuan,the carbon storage in grassland ecosystem in Sichuan was estimated. The results showed that the total grassland area in Sichuan was about 22.43×10⁴ km² in 2008, and the total carbon storage in the grassland ecosystem in Sichuan was 2 302.97 Tg. The aboveground and underground carbon storage was 15.54 and 104.45 Tg C respectively. The underground carbon storage was about 6 times more than the aboveground; the soil organic carbon in Sichuan grassland was 2 182.98 Tg, which was about 19 times more than the vegetation carbon.