Grassland ecosystem shows an obvious degradation trends in Qinghai-Tibetan Plateau due to global warming and intensity human activities. Many methods have been developed to monitor the grassland degradation. As a representative method,remote sensing technology provides a wide,quick,and accurate approach to reveal the process of grassland degradation. One of the important characteristics of grassland degradation is the decline of vegetation coverage. MODIS data are used to describe the grassland coverage status. Results show that the grassland vegetation coverage remains an upward trend from 2000 to 2011. The upward trend is divided into five grades, which are severe deterioration, slight deterioration, unchanged,slight melioration, obvious melioration. In the source of Yellow River, the trend is more obvious and mainly obvious melioration grade. The restoration process of grassland in the Three-River source region is a fluctuant procedure,while it is steadier in the source of Yellow River. The vegetation coverage is widely recovered in the most area of the Three-River sources region after ecosystem engineering. The decline of vegetation coverage is mainly occurred in the central of Yushu, part of Zaduo and in the eastern of the Three-River sources region.