Abstract: In most studies,the ichthyoplankton have been identified by morphological characteristics.Previous studies have shown that DNA barcoding can be used to identify the early life stages of fish more accurately than traditional morphological methods.To study the applicability of this technique to identify ichthyoplankton,samples were collected in Xiamen Bay in April 2017.A total of 27 valid cytochrome C oxidase subunit I(COI) gene sequences of ichthyoplankton were obtained.Eleven species were identified to the level of species.All sequences formed species units in a neighbor-joining phylogenetic treebased on Kimura-2-parameter(K2P) distances,indicating that the DNA barcode could be used to identify these 11 species.Consequently,COI barcoding was one of the useful tools to identify ichthyoplankton.The results demonstrated that DNA barcoding was a powerful complement to traditional morphology,and an accurate,standardized,and efficient tool for ichthyoplankton species identification,and possessed a broad prospect of application in fish biodiversity research.