Abstract： Objective To investigate the relationship between human leptin receptor(LEPR)gene G3057A polymorphism and type 2 diabetes complicated with non-alcoholic fatty liver disease(NAFLD).Methods 216 cases of newly diagnosed type 2 diabetes(104 cases complicated with NAFLD)and 108 cases of normal glucose tolerances(NGT)were recruited.Hemi-nested PCR-RFLP and PCR direct sequence analysis were conducted to detect the polymorphisms of LEPR G3057A polymorphism.The plasma leptin and insulin levels were measured by ELISA kit.Plasma lipid and glucose metabolic parameters were measured routinely.Liver ultrasound scanning Was carried out among all subjects.Results Type 2 diabetic patients complicated with NAFLD had higher plasma alanine aminotransferase(ALT),triglycerides(TG),low density lipaprotein cholesterol(LDL-C),leptin levels and lower plasma insulin levels than those cages without NAFLD and NGT.The variant frequency at nucleotide 3057 G to A transversion Was 76.0% in type 2 diabetic patients complicated with NAFLD,which Was also significant higher than those cases without NAFLD(62.1%)or NGT cases(53.2%)(x2=14.63,P＜0.01).Conclusions The polymorphism of LEPR gene 3057 probably contributes to the onset of NAFLD in type 2 diabetes by regulating lipid metabolism and affecting insulin sensitivity.