Abstract： Objective To explore the relationship of fasting serum resistin with obesity and insulin resistance in patients with obesity and newly diagnosed type 2 diabetes. Methods The obese patients with T2DM (n=48), non-obese patients with type 2 diabetes (n=48) and healthy controls （n=50） were enrolled. Fasting serum levels of resistin, glucose, lipids and insulin were measured. Their body height, body weight and blood pressure were measured and BMI and HOMA-IR were calculated. Results （1）Compared with control and patients with non-obese type 2 diabetes, the level of serum resistin in obese patients with type 2 diabetic was much higher (P<0.01). （2）The level of serum resistin was correlated with HOMA-IR, BMI and triglyceride (P<0.01). Conclusion The serum resistin level in patient with type 2 diabetic is elevated and correlated with obesity and insulin resistance. Resistin may play a pivotal role in the development of type 2 diabetes.