Abstract: This study detected Epichloё endophyte in the seeds of eight collections of Festuca sinensis, collected from Qinghai, Gansu, Sichuan and other parts of China, with an infection rate of 100%. This provided excellent material to evaluate the taxonomic status of Epichloё endophyte in F. sinensis. A phylogenetic tree was constructed with actin gene sequences by cloning from the collected F. sinensis seeds and comparison with published actin gene sequences downloaded from GenBank. The actin sequences of Epichloё endophyte strains isolated from the eight F. sinensis accessions were clustered together and formed a separated clade, which suggests that endophyte strains in different F. sinensis accessions belonged to the same taxon, but may be a new species. Moreover, population genetic distance analysis also confirmed these 8 Epichloё strains to be conspecific. The phylogentic tree also distinguished Epichloё endophyte strains isolated from F. sinensis at the same or nearby sampling sites from strains collected from more distant sites. In summary, the findings indicate a possible new species of Epichloё in F. sinensis, with distinct strains at geographically different sampling sites.