DNA barcoding provides an efficient method for species-level identifications. In this study, we have amplified partial sequences of mitochondrial cytochrome c oxidase I (COI) gene from 110 specimens of 45 species of Caenogastropoda collected from the coast along China to evaluate whether DNA barcodes can distinguish these species accurately. The average Kimura 2-parameter (K2P) distances within species, genera and families were 0.44%, 13.96% and 22.27%, respectively. Both the neighbour-joining tree and the Bayesian tree showed a clear discrimination of all the species in our study with highly supported clades. These results proved that the species of Caenogastropoda can be efficiently and accurately identified by DNA barcoding based on the COI gene.