Abstract:  A preliminary study was carried out to investigate the biological characteristics， infection rate of a fungus isolated from Ophicordyceps sinensis， as well as its relationship with Ophicordyceps sinensis， and the molecular identification was analyzed. The results showed that the optimum temperature and pH for culture was 20 to 23 ℃ and 7.50 respectively. The optimum carbon sources and nitrogen sources was sucrose and bran. The infection rate on Hepialidae larva was 100%. The inhibition rate on Ophicordyceps sinensis was 43.37% in flat confrontation test. PCR results showed that about 560 bp ITS fragments were amplified from the mycelium. Phylogenetic analysis indicated that the fungi belonged to Beauveria， and GenBank accession number is KP284435.

Key words: Beauveria, Ophicordyceps sinensis, biological characters, infection