Abstract: During July to August of 2010, field investigations by quadrat and line transect method were conducted on species composition of plantcommunities in the ecotone of desert and oasis in the upper reaches of Tarim River, Shaya county, Xinjiang UygurAutonomous Region. Analysis wascarried out on diversity of the research area by Margalef richness index, Shannon-Wiener index, Pielou evenness index and ecological dominance.The results showed that there were14 species plant of 9 families, and could be divided into 6 community types. The plant communities had evidentlayers and simple structure. The mean density of arbors was 771.1 trees/ha, that of shrub 1 413.3 trees/ha, and that of herb 864.9 clump/ha. Margalefabundance index was 1.47, Shannon-Wiener index1.62, Pielou evenness index 0.61 and ecological dominance 0.26. The investigation and analysisresulted that species in the communities near the River had more diversities.