Abstract： Objective To investigate the relationship between plasma leptin levels and obesity,plasma glucose as well as insulin concentrations.Methods Fasting plasma leptin concentrations were measured with IRMA in 171 cases (including 84 type 2 DM,36 IGT,51 NGT;90 men,81 women),and oral glucose tolerance test was done in every case to measure plasma glucose and insulin concentrations.Height,body weight were measured to calculate body mass index (BMI).Results Fasting plasma leptin levels are correlated with BMI( r=0.6772,P <0.01 in male and r=0.7191,P <0.01 in female),and leptin levels were 2～3 times higher in female than in male ( P <0.001).The stepwise multiple regression analysis shows that leptin variations were positively correlated with insulin curve areas.Conclusion Fasting plasma leptin levels are higher in obese subjects than that in non obese ones.The correlation between hyperleptinemia and hyperinsulinemia suggests a possible role for leptin in type 2 diabetes pathogenesis.