Chinese caterpillar fungus (Cordyceps sinensis) has been widely and famously used as a precious tonic in the long history of Asian medicine.Because the price of C.sinensis is higher than that of gold,counterfeits of C.sinensis have appeared on the market and are difficult to identify because they are morphologically very similar to C.sinensis.In this study,the DNA barcode ITS/ITS2 was used to distinguish between C.sinensis and counterfeits or closely related species.The PCR amplification efficiency,differential intra-and inter-specific divergences,DNA barcode gap,and identification ability were used to test the applicability of this DNA barcode.A total of 131 ITS/ITS2 sequences of C.