Abstract: For the soil restoration of degraded grassland in Tibet and maintenance of the grassland ecosystem balance,it is necessary to study on grassland degradation and its causes.This paper systematically describes the present state and characteristics of grassland degradation in Tibet plateau,making an in-depth analysis of the natural and man-made causes leading to the degradation.The results show that the material basis is unstable geomorphology,shallow soil,coarse particles of soil,gravel,poor soil consolidation,erodible soil.Global warming,low precipitation and strong evaporation,frequent strong winds,erosion of freezing and thawing are the dynamic stimulation.The key factors leading to grassland degradation are continuously overloading grazing and other man-made excessive interventions.