The gene fragments of the mitochondria COI and 16S rRNA in P. laevis, P. amurensis, P. ustulata and P. rubromuscula were amplified and sequenced. Totally, 40 sequences of COI gene and 16S rRNA were obtained,and they were 650 bp and 450 bp in length after trimming，respectively. It showed a low G+C base composition (38.6%). The result of sequence analysis showed that the intraspecific variation and interspecific variation were lower in 16S rRNA than those in COI gene. 10 mutation sites and 7 haplotypes were detected in the gene fragments of 16S rRNA. Taking M. arenaria as the out-group, the phylogenetic trees were constructed using the method of NJ with the software MEGA4.0. Based on the genetic distance and NJ phylogenetic tree，we found that the four speices of Potamocorbula failed to achieve significant genetic differentiation between species.