Abstract: In this study, the "Levins" method, variance ratio method (VR), chi-square test, association coefficient (AC) and Ochiai (OI) index were used to analyze eight major plant species in the dominant plant communities in the temperate grasslands of the Kuizu Mountains of Tibet, in order to reveal the effects of non-grazing restriction on the ecological niches and interspecific associations of the herbaceous species in the dominant plant communities in the temperate grasslands of the Kuizu Mountains of Linzhou County, Lhasa River Basin, so as to provide theoretical basis for the protection of the plant diversity of the temperate grasslands of the Tibetan Plateau and for the scientific management of the grasslands.The results showed that : (1)non-grazing treatments increased the niche width and niche overlap of grass sedge (Tripogon bromoides), alpine tarragon (Carex parvula), whitegrass (Pennisetum flaccidum), and silky needle fescue (Stipa capillacea).(2) The enclosure community in the study area showed an overall negative association (VR=0.43), and the free-grazing community showed an overall positive association (VR=1.21);According to the Chi square test, the 50% and 42.9% of the 28 species pairs composed of 8 dominant species displayed negative association under the non-grazing and free grazing treatments;The association coefficient showed that 50% and 42.9% of species pairs were negatively linked under the non-grazing and free grazing treatments;respectively. The OI index showed that non-grazing treatments increased the OI values of the main species(Tripogon bromoides, Carex parvula, Pennisetum flaccidum and Stipa capillacea). Based on the interspecific association analysis, non-grazing treatments has strengthened inter-species competition within the dominant plant communities in the temperate grasslands of Kuizu Mountains, and inter-species relationships have become tighter, with the community structure stabilized.