To study the polymorphism of the proopiomelanocortin (POMC) gene and establish the molecular genetic marker for identifying different population of Pelodoiscus sinensis,populations from Taihu Lake,Huanghe River,Taiwan-introduced and Pelodiscus axenaria,were collected to get the blood.The POMC gene was amplified by RT-PCR,sequenced and analyzed thereafter.Fifteen SNPs were detected in the PCR-amplified 786 bp fragments.One SNP at nucleotide 129 in Taiwan-introduced population,one SNP at nucleotide 441 in Taihu Lake population,two SNPs at nucleotide 168 and 396 in Huanghe River population,and two SNPs at nucleotide 531 and 618 in P.axenaria were identified.The results showed that the POMC gene of P.sinensis showed polymorphic,the POMC gene of different population has specific mutation site,which can be used as a molecular genetic marker for identifying different population of P.sinensis.