The natural diet of goitred gazelle (Gazella subgutturosa) was studied over the period of a year in northern Xinjiang, China using microhistological analysis. The winter food habits of the goitred gazelle and domestic sheep were also compared. The microhistological analysis method demonstrated that gazelle ate 47 species of plants during the year. Chenopodiaceae and Poaceae were major foods, and ephemeral plants were used mostly during spring. Stipa glareosa was a major food item of gazelle throughout the year, 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 extremely warm and dry weather during summer and autumn, succulent plants like Allium polyrhizum, Zygophyllum rosovii, Salsola subcrassa were favored by gazelles. In winter, goitred gazelle and domestic sheep in Kalamaili reserve had strong food competition; with an overlap in diet of 0.77. The number of sheep in the reserve should be reduced to lessen the pressure of competition.