Cordyceps is an important biological resource in China, in order to clarify the species of a wild cordyceps collected from Shimen Mountain Forest Area in Xunyi County of Shaanxi Province and the taxonomic status of its entomogenous fungus (cordyceps fungus DY6F), the gene fragments of internal transcribed spacer (ITS), elongation factor 1α (EF-1α) and RNA polymerase Ⅱ large subunit (RPB1) of cordyceps fungus DY6F were amplified and sequenced by using PCR technique. Subsequently, the phylogenetic trees based on ITS, EF-1α and RPB1 gene fragment, respectively, as well as a multilocus phylogenetic tree based on EF-1α and RPB1 combined nucleotide sequences were constructed. According to the results, the similarity between these three gene sequences of cordyceps fungus DY6F and the corresponding gene sequences of Ophiocordyceps nigrella was 99-100%. In the evolutionary tree, cordyceps fungus DY6F and Ophiocordyceps nigrella were clustered into one branch, with an approval rating of 100%. Therefore, the cordyceps fungus DY6F was identified as Ophiocordyceps nigrella.