Abstract: Objective:To investigate the association of urotensin Ⅱ(UⅡ)gene S89N polymorphism with type 2 diabetes mellitus(T2DM)and obesity.Methods:One hundred and five patients with T2DM(53 obesity,52 normal)and 114 non-diabetic subjects(55 obesity,59 normal)in Bengbu,Anhui province were randomly selected in the study.The polymerase chain reaction restriction fragment length polymorphism and the gel electrophoretic mobility shift assay were used to examine the S89N polymorphism.Results:The frequency of the Ser/Ser genotype was 64.9% in non-diabetic subjects and 52.4% in T2DM patients.The Asn/Asn frequencies were 5.3% and 16.2% in the two groups respectively.The difference was significant(P0.05).The genotype S89N of UⅡwas related with T2DM(P0.01),but not with obesity(P0.05).The difference of metabolic indexes of FPG,PBG,FINS INS2h,HOMA-Ir,ISI and TG among three genotypes of UⅡ in T2DM group was significant(P0.05-P0.01).The difference of metabolic indexes of CP and CP2h between Asn/Asn and the other two genotypes of UⅡ in T2DM group was significant(P0.01).Conclusions:The UⅡ gene S89N polymorphism is significantly associated with T2DM,but not with obesity among the Han population in Bengbu city.