中文摘要：

目的探讨Sinopotamon.fukienense与S.xiusuiense间的的遗传分化。方法采用PCR结合DNA测序技术,测定两种华溪蟹S.fukienense与S.xiusuiense线粒体16SrRNA基因序列的组成和变异。经比对获得513bp的核苷酸序列,以分析S.fukienense与S.xiusuiense间的的遗传分化。结果数据显示S.fukienense和S.xiusuiense两个群体之间的遗传距离为0.032±0.006,遗传分化指数（Fst）为0.70336,基因流（Nm）为0.11。结论这表明两群体间高度分化,基因交流很少。重建的系统发生显示它们各自形成独立的分支,这与形态学鉴定结果基本一致。

英文摘要：

In order to explore the genetic differentiation between the freshwater crabs S.fukienense and S.xiusuiense,the base composition and sequence variation of 16S rRNA in the populations of S.fukienense and S.xiusuiense were studied by the methods of PCR and DNA sequencing.We obtained 513 bp nucleotide sequences by comparison and analyzed the genetic differentiation between S.fukienense and S.xiusuiense.The average genetic distance（P） between the two populations was 0.032±0.006,the index of genetic differentiation（Fst） was 0.703 36 and the gene flow（Nm） was 0.11.The molecular biology result indicates the high degree of differentiation between S.xiusuiense and S.fukienense.There is no gene flow between them.Phylogenetic reconstruction shows the two clades phylogenetic tree are discernible.Also the molecular evidence supports that the monophyly of the S.fukienense and S.xiusuiense clades corresponds with their morphological differences.