In order to investigate the morphological and mitochondrial gene genetic diversity of Corbicula fluminea in different reaches of Minjiang River.A total of 180 C.fluminea samples randomly collected from 6 geographical locations in Minjiang River [(Yanping,YP),(Minhou,MH),(Longxiangdao,LXD),(Mawei,MW),(Changle,CL) and (Lianjiang,LJ)].Morphological data were measured and partial sequences of mitochondrial COⅠ,Cyt b and 16S rRNA genes were used as molecular markers for PCR amplification and sequencing analysis.The results showed that the coefficient of variation of shell length,shell height and shell width was small,while the coefficient of variation of soft body weight,shell weight and total weight was large of C.fluminea in six reaches of Minjiang River.The population with the largest coefficient of variation of soft body weight was LJ (53.30%).The sequences of mitochondrial COⅠ,Cyt b and 16S rRNA genes were 444,466 and 364 bp,respectively.The content of A+T in the three genes was similar and significantly higher than that of C+G.The number of haplotypes of COⅠand Cyt b genes were significantly more than that of 16S rRNA gene.The genetic diversity of COⅠ and Cyt b genes were higher than that of 16S rRNA gene.Phylogenetic tree showed that the evolution rate of the three gene fragments were COⅠ> Cyt b >16S rRNA gene.The neutral test and mismatch distribution analysis showed that the C.fluminea populations in Minjiang River were stable and there were no history of large-scale population expansion.In conclusion,there was no significant difference in the morphology of C.fluminea in the six reaches of Minjiang River.COⅠand Cyt b genes of C.fluminea have higher genetic diversity and faster evolutionary speed than 16S rRNA genes.Even though independent genetic populations have been differentiated,there has no historical event such as large-scale population expansion.Therefore,C.fluminea could be protected and developed as a whole in Minjiang River.