DNA barcoding has exhibited charming effectiveness in species diagnosis, but some studies suggested the proportion of taxa that cannot be barcode-distinguished was still high. In the present study, the efficiency of the DNA barcoding for delimiting species of subfamily Tapetinae along the coast of China was tested. Fifty one original COI sequences of 11 species in five genera were analyzed. Among these sequences, 43 haplotypes were identified. Saturation plots generated for DNA barcode revealed that transitions became saturated after 10% to 15% sequence divergence. However, transversions were not saturated. Excluding Ruditapes variegata
haplotype Hap33 that might be the result of a hybridization event, our finding showed that K2P-distances between conspeci?c sequences varied from 0% to 2.02% (0.46% on average), distances between congeneric sequences were from 17.21% to 32.24% (24.96% on average), and all conspeci?cs clustered together in the phylogentic trees. The proportion of individuals that can be distinguished by DNA barcoding was approximately 98% among 51 individuals analyzed in this study. Thus, the results evidenced that subfamily Tapetidae species can be efficiently identified through the use of DNA barcoding.