To investigate the influences of beta3 adrenergic receptor(beta3AR) Trp64Arg polymorphism on insulin resistance.The insulin sensitivity was estimated with logarithm transformed homeostasis model assessment (HOMA). We enrolled 88 pairs of dizygotic twins for this study. We performed PCR-RFLP analysis to detect the Trp64Arg variants with BstO I digestion.The genotypic frequencies of Trp64Trp, Trp64Arg and Arg64Arg were 71.5%, 26.7% and 1.7%. Those who carried Trp64Arg variant appeared to have lower insulin sensitivity compared to the one who didn't, but had no significance(P=0.145). Body mass index (BMI) had shown to be weakly positive correlated with lgHOMA. We found no significant association between the Trp64Arg variant and BMI.The presence of the Arg64 allele in beta3AR gene may predispose patients to insulin resistance, and further study with larger sample size may help to confirm the result.