enetic structure of populations is greatly influenced by the dispersal ability of marine organisms. It seems intuitive that limited dispersal capability should result in greater genetic differentiation. is a typical cephalopod species which shows limited dispersal potential. In this study, the effect of dispersal capability on population genetic structure was tested on in coastal waters of China, by applying mitochondrial gene sequencing technology. A 485 bp segment of the 16S rDNA gene was sequenced and analyzed in 100 specimens. populations. Two distinct clades with 14 fixed nucleotide base variation region were detected: one was composed of four populations from northern coastal waters, including Dalian, Yantai, Qingdao, Lianyungang populations, the other consisted of three populations from southern coastal waters including Shanghai, Zhoushan, Guangzhou populations. The between the two clade were high, which amounted to 0.878 and 0.069, respectively. AMOVA test, which showed 12.24% of the genetic variation lied within populations and 87.76% lies between populations, further suggested there was genetic differentiation between the two lineages. The net genetic distance between the two lineage was 0.019, suggesting a moderate and intraspecific level of differentiation. The two lineages may diverge in late Pleistocene, suggested by molecular clock analysis. The divergence might be resulted from low dispersal ability in at both larva and adult stages. Pattern of isolation by distance was observed in this species, further verifying this point of view. The frequent osilation of sea level during the late Changjiang might also play an important role in the formation of genetic structure in China coasts. These findings will have important implications for better exploitation and protection of China in the near future.