Objective: Based on the DNA barcoding technology

a method of investigating medicinal sources for poisonous herbal medicine(Bungarus Parvus) was established to investigate medicinal sources of this medicine in Chinese herbal markets and drug stores. Method: Firstly

a reference cytochrome C oxidase subunit I (CoⅠ) barcode library was established for the authentic Bungarus Parvus and its main adulterants.Then

51 samples of the commercially available Bungarus Parvus were collected from herbal markets and drug stores

and then CoⅠ sequences for the head and the tail tissue of each samples were obtained.Finally

the species identification of head and tail tissues of these commercially available samples was achieved by constructing the neighbor-joining(NJ) phylogenetic tree. Result: A total of 60 CoⅠ sequences were obtained from the authentic Bungarus Parvus and its main adulterants.The maximum intra-specific variation of Bungarus multicinctus was 0.020 1

whereas the minimum inter-specific variations of B. multicinctus and their main adulterants (B. fasciatus

Lycodon rufozonatus and Sinonatrix annularis) were 0.156 1

0.208 8 and 0.209 3

respectively;the maximum intra-specific variation of B. multicinctus was less than its minimum inter-specific variations.The authentic Bungarus Parvus and its main adulterants showed independent branches in the NJ phylogenetic tree and could be discriminated clearly.CoⅠ sequences could be successfully obtained from both the head and the tail of all the commercially available Bungarus Parvus samples and the investigation results showed that 29 of B. multicinctus

20 of L. rufozonatus and 2 of S. annularis.The total of adulterants accounted for 43% and the results based on heads and tails were the same. Conclusion: DNA barcoding technology can be used to investigate the medicinal source of the commercially available Bungarus Parvus.The market of Bungarus Parvus is in disorder and has serious quality problems with a lot of adulterants.