Abstract: Twenty three strains of endophytic bacteria were isolated from the roots and seeds of dormant plants in winter of two species of Kobresia, using the dilution plate method. The isolated bacteria were identified by sequence analysis of their 16S rDNA. Then their biological properties, including antimicrobial activity, phosphorus solubilisation, nitrogen fixation and production of IAA, were determined. There were significant differences in the number of endophytic bacteria and their community composition in the roots and seeds of the two Kobresia species. Kobresia capillifolia had a higher species diversity of endophytic bacteria than Kobresia humilis. Endophytic bacteria were more abundant in roots than in seeds for K. humilis, but the opposite was true in K. capillifolia. The amount of endophytic bacteria was affected by the seed storage time. Twenty strains among the isolated endophytic bacteria displayed biological activity. including antimicrobial properties, phosphorus solubilisation, nitrogen fixation and production of IAA. The, numbers of strains with these respective capabilities were 35%, 55%, 45% and 25%, respectively, of the total number of bacteria. Fifteen taxa were identified among the 16S rDNA gene sequences of the endophytic bacteria isolated. They included the genera Bacillus, Phyllobacterium, Staphylococcus, Paenibacillus, Microbacterium, Promicromonospora and Sphingopyxis. Among these, Bacillus was the dominant species.