@@1. Anthropogenic activities (overgraze) lead to alpine grassland deterioration, and the areas of weeds are expanding gradually in the Qinghai-Tibet Plateau, and the natural environment of the region is extremely harsh, the soil is generally quite thin. Once the vegetation is disturbed or degraded it is difficult to get it to recover. Understanding competitive abilities of dominants and companions may help in rehabilitating the deterioration area of grassland ecosystem, and it is necessary to predict how changing species will enhance the ecological protection.