Using DNA barcode to identify species of puffer fish in roasted fish fillet and dried fish sold in Beijing and Xiamen markets.Methods Genome DNA from roasted fish fillet and dried fish was extracted, amplified by specific primer of cytochrome oxidase subunit Ⅰ of puffer fish and sequenced. BLAST comparison was made between the sequencing results and Genebank, and phylogenetic tree was built. Results Specific straps were amplified by PCR in 15out of 27samples. According to the BLAST comparison and phylogenetic tree analysis, the 15samples were classified in different puffer fish species.Conclusion Some commercial roasted fish fillet and dried fish was made by puffer fish in Beijing and Xiamen. The supervision should be strengthened and the processing procedures should be standardized to avoid tetrodotoxin poisoning.