The PCR technique was used to amplify the partial mtDNA COI gene of 11 species of Viperidae and Elapidae snakes collected from Taiwan. The PCR products were sequenced and 658 bp of COI gene were obtained. The average Kimura-2-parameter genetic distance intra-species was 0.04 ~ 2.40%, and the inter-species was 1.45 ~ 25.48%. The phylogenetic trees estimated by neighbor-joining method and maximum-parsimony method obtained similar results. All 11 snake species showed monophyletic and every species could be discriminated clearly. It is suggested that the COI barcoding can be used to identify Viperidae and Elapidae snakes species in Taiwan.