Abstract: We studied the flora and composition of seed plant species in the Kumtag Desert, a typical region in northwest China, by field investigation and remote sensing. The results showed that: (1) There were 143 plant species belonging to 29 families and 91 genera. Among these species, annual and perennial plants were the main life forms. The species composition was deficient, and plant life-form was simple. (2) The Aqik Valley, piedmont alluvial-pluvial fan of the Arjin Mountain, and Xihu Wetland formed three distinct seed plant distribution areas in the Kumtag Desert, which were influenced by water, high temperature and soil salinity. The differences in species composition for the three regions were significant. (3) The life forms in the piedmont alluvial-pluvial fan of the Arjin Mountain were richer than those in the Aqik Valley or Xihu Wetland. Additionally, the piedmont alluvial-pluvial fan of the Arjin Mountain had the richest families, genera and species. Higher similarities in genus and species were observed between the Aqik Valley and Xihu Wetland. (4) Chenopodiaceae, Compositae and Ephedraceae were the dominant families in the Kumtag Desert. The main distribution pattern of the families in the three regions was Cosmopolitan. The main geographical elements of all genera in the Kumtag Desert were Mediterranea. W. Asia to C. Asia in the Aqik Valley and Xihu Wetland, and North Temperate in the piedmont alluvial-pluvial fan of the Arjin Mountain. (5) Compared with the near desert regions, the ratio of xerophytes was higher in the Kumtag Desert, and the relic nature was more obvious. Special seed plant taxa and flora features were formed because of the particular Kumtag Desert environment.