Abstract:In order to analyze the molecular phylogenetic relationships of Scolopsis fish in China sea as well as investigate the applicability of COⅠ gene as a DNA barcode for the Scolopsis species identification, partial sequences of COⅠ genes of 9 Scolopsis species were amplified and sequenced, in this study. Combining with 5 COⅠ sequences obtained from GenBank, the molecular phylogenetic relationships of 14 Scolopsis species were constructed and analyzed. The results indicated that: the average intra-species genetic distance values of 14 Scolopsis species was 0.002 5, while the average inter-species genetic distance value was 0.179 4, which was 71.76 times of the former. In the molecular phylogenetic tree, 14 species mainly formed three groups. Group Ⅰ included 4 Scolopsis species, that had big sharp bone below the eyes, which was consistent with morphological classification; Group Ⅱ included 4 species and the Group Ⅲ included 6 species, however the noding support values were relatively low in some branches, indicating that COⅠ gene can be used as an effective DNA barcode gene to distinguish species, but may not suitable for molecular phylogenetic analysis. In addition, the COⅠ genetic distance values of certain species which under morphological synonyms argument (Scolopsis taenioptera+Scolopsis bimaculata,+ Scolopsis monogramma and Scolopsis affinis + Scolopsis aurata) were revealed to be 0.160, 0.118, and 0.122, respectively. The values were all far greator than the minimum distance value (2%) in distinguishing different species recommended by Hebert, suggesting that they should be independent species.