Abstract：We quantified food habits of goitered gazelle (Gazella subgutturosa sairensis)and domestic sheep at Kalamaili Mountain Nature Reserve in northern Xinjiang,October 2006 - August 2007,using faecal microscopic methods. We identified 47 plant species in goitered gazelle fecal samples,representing 16 families. Diets varied seasonally:in autumn,we documented 24 plant species from 7 families consumed by gazelles;in winter,gazelles consumed 17 plant species from 6 families;41plant species from 16 families used by gazelle in spring;and 30 plant species from 12 families used by gazelles in summer. Chenopodiaceae and Gramineae were major foods of goitered gazelles,comprising 38.8 -85.1% ,and the forbs were often grazed by the gazelle;spring ephemeral plants and ephemeroid plants were very important to the gazelle,comprising 27% of its spring food components. Over all seasons,Stipa glareosa was a major food of gazelles,Ceratoides latens was mainly used in spring and summer,whereas in autumn and winter,gazelles consumed a large amount of Haloxylon ammodendron. Because of the hot and dry climate,forbs with higher water content,such as Allium polyrhizum,Zygophyllum rosovii,Salsola subcrassa were favored by gazelles. In winter,domestic sheep had similar food niche breadth with goitered gazelle,and food overlap index was 77% .