Abstract: The grazing intensity changes the plant composition of alpine meadow. A field survey was carried out to determine the effect of grazing intensities on plant niche characteristics of alpine meadow communities in the Qinghai-Tibet Plateau. This study showed that the number of plant species appearing in plots reduced as the grazing intensity increased, and Anaphalis tibetica, Stipa purpurea and Allium sikkimense disappeared when grazing intensity exceeded 1.25 yak/ha. The numbers of unpalatable plants increased when the grazing intensity in plots was over 1.00 yak/ha. With increasing grazing intensity, the importance value of Kobresia capillifolia, a dominant species, initially increased and then decreased, peaking at 1.00 yak/ha grazing intensity, and the importance value of Polygonum viviparum, another dominant species peaked at 0.75 yak/ha grazing intensity. The niche breadth of K. capillifolia and P. viviparum was greater than that of other species in alpine meadow communities differing in grazing intensity and increased as the grazing intensity increased. The plants with the biggest niche overlap with K. capillifolia and P. viviparum were different. P. viviparum was one of two populations which had a bigger coefficient of niche overlap at 0 and 0.75 yak/ha grazing intensity, however, P. viviparum did not appear in the populations which had the biggest coefficient of niche overlap when the grazing intensity was over 0.75 yak/ha. K. capillifolia was one of two populations which had the biggest coefficient of niche overlap at 1.25 yak/ha grazing intensity. These results suggest that the grazing intensity changed the plant composition, species importance values, niche breadth and niche overlap of alpine meadow communities, and that a grazing intensity of 1.00 yak/ha was advantageous to the dominant species, P. viviparum and K. capillifolia, in alpine meadow at the northeastern edge of the Qinghai-Tibetan Plateau.