Abstract: Objective To ascer tain the associat ion of the T rp64Arg mutation in the beta 3-adrenergic receptor(β₃-AR) gene with the non-insulin-dependent diabetes mellitus(NIDDM).Methods One hundred thirty patients with NIDDM and 130 controls were selected.The β₃-AR genotype status was determined by polymerase chain reaction(PCR)and restriction fragment length polymorphism analysis(RFLP).Body mass index (BMI),waist-hip ratio(WHR),blood pressure,TC,TG,HDLC,ApoA,ApoB,Lp(a)were detected.Results(1)The frequency of Arg64 allele of β₃-AR gene in NIDDM(14.7%)was slightly higher than that in control(14.2%).Genotypes and the frequency of Arg64 allele do not exist differnece between two groups(P> 0.05).(2)The Trp64Arg mutation in the β₃-AR gene was associated with BMI in NIDDM(P=0.0055).The frequencies of Arg64 allele were 19.8% and 5.7% in female diabetes with obesity and normal-weight respectively.The mutation exists significantly positive relationship with BMI(P=0.010).Conclusion These results suggest that the Trp64Arg mutation of the β₃-adrenergic-receptor gene in the non-insulin-dependent diabetes mellitus is associated with obesity.