【目的】基于哈密市荒漠草地生态环境脆弱的实际状况，本研究旨在分析哈密市荒漠草地物种多样性和生态位特征，为哈密荒漠草地生态系统的保护和修复提供数据支撑。【方法】通过开展野外实地调查，结合生态位理论研究方法，计算哈密市荒漠草地植物多样性及其优势物种的生态位特征。【结果】结果显示，哈密市荒漠草地植物包括15科33属45种，以藜科植物为主，哈密市东天山南坡、北坡荒漠草地植物多样性没有显著差异；哈密市荒漠草地优势植被生态位宽度在0.006～1.283之间，生态位重叠的物种对有25对，其中膜果麻黄（Ephedra przewalskii Stapf）和木霸王（Sarcozygium xanthoxylon Bunge）的生态位重叠值最高。【结论】哈密市荒漠草地物种分布以藜科植物为主，天山南北气候差异对其荒漠草地植物多样性影响不显著，且优势植被生态位宽度、物种间生态位重叠值均不高，这说明哈密荒漠草地优势植被种间对环境资源的需求相似度不高，竞争不强。在实施荒漠草地生态修复的过程中要选择生态位宽度较宽的植被。

【Objective】Based on the actual situation of the fragile ecological environment of the desert grassland in Hami City,this study aims to analyze the species diversity and niche characteristics of the desert grassland in Hami City,and lay the foundation for the protection and restoration of the desert grassland ecosystem in Hami.【Methods】Vegetation diversity of desert steppe in Hami City as well as the niche characteristics of dominant species was calculated by field investigation in combination with theoretical research method of niche.【Results】There were 45 species of 33 genera of 15 families plants in the desert steppe,mainly Chenopodium. No significant difference was observed in plant diversity between south and north slopes of east Tianshan Mountains.The niche width of dominant vegetation in the desert steppe in Hami City ranged from 0.006 to 1.283,and there were 25species pairs with overlapping niches,among which,Ephedra przewalskii Stapf and Sarcozygium xanthoxylon Bunge had the highest overlapping value.【Conclusion】Chenopodium was the dominant species of desert steppe in Hami City,and the difference of climate between north and south Tianshan Mountains had no significant effect on vegetation diversity. The niche width of dominant vegetation and overlapping value between species were not high,indicating that the demand for environmental resources between dominant vegetation species in desert steppe was not very similar,hence the competition was not strong. In the process of ecological restoration of desert grassland,vegetation with wide niche width should be selected.