Abstract: It is well known that Stromateidae species are important commercial fishes. Only the Pampus species are found along the coast of China, while both Peprilus and Stromateus are distributed in the Atlantic and East Pacific. In this study, morphological characteristics and DNA barcoding technology were used to identify the species of “Nanchang” collected from Hainan, Guangdong and Guangxi. Meanwhile, the COⅠ gene homologous sequences of this species were downloaded for comparative analysis, and the wrong sequences in GenBank were corrected. The results indicate that the scientific name of “Nanchang” is actually Peprilus medius, which is a frozen specimen imported from South America. There are no reports on the distribution of this species in the coastal areas of China, and there are obvious differences between P. medius and six Pampus species in China in the external morphology of gill rake, dorsal fin and gluteal fin. The genetic distance between P. medius and Pampus species at the COⅠ gene level is 0.138, which were differentiated from the late Miocene. This study has provided a reference to the identification of commercial aquatic species, as well as basic data and a reference for Stromateidae and other marine fish taxonomy.