Abstract:From April to July, 2004 and 2005, the nest\|site selection of the Himalayan Snowcock(Tetraogallus himalayensis) was investigated by the direct observation and plot sampling method in the field, at the Dongdashan Nature Reserve in Zhangye, Gansu Province. Totally 36 nests were measured in the field work. The Himalayan Snowcock exhibited a preference to a relative place (2601-3000 m elevation), a mountainous grassland with rocks, a bare rock zone, a thicket grass, and a place beneath a overhanging rock and shrubs, where was over the mountainside and the gradient ranged from 26°-40° on sunny slopes and semi\|sunny slopes. Based on the principal components analysis, predation and food were the two main factors affecting the nest\|site selection of the species. The primary factors in the following order: the height of shrubs, the distances to cliff, the cover degrees of grass, the density of shrubs and species diversity. We concluded that, as a result of trade\|off between two main factors, the nest\|site selection in our study is of great benefit to the Himalayan Snowcock to survival. Furthermore, the cliff factor (the distances to cliff and cliff number in 500m）takes on obvious effect on nest\|site selection, this maybe related to the escaping pattern and weak flying ability of Himalayan Snowcock.