Objective To investigate the changes and clinical significance of serum total and high molecular weight adiponectin (HMW APN) levels in type 2 diabetic patients with non-alcoholic fatty liver disease (NAFLD).Methods Serum levels of total adiponectin and HMW APN were measured by ELISA,in 58 type 2 diabetic patients with nonalcoholic fatty liver disease (T2DM with NAFLD group),59 type 2 diabetic patients without nonalcoholic fatty liver disease (T2DM group),and 55 control subjects with normal glucose tolerance and without nonalcoholic fatty liver disease (NC group).Results (1) Alanine transaminase and total cholesterol levels were significantly higher in T2DM with NAFLD group than those in NC group(P＜0.01),while body mass index (BMI),aspartate aminotransferase,triglyceride (TG),and fasting insulin were also significantly increased (P＜0.05 or P＜ 0.01),and high density lipoprotein-cholesterol (HDL-C) were significantly decreased compared with those in NC and T2DM groups (P＜0.01).(2) Total adiponectin,HMW APN,and the ratio of HMW APN to total adiponectin in T2DM group were lower than those in NC group.Total adiponectin and HMW APN levels in T2DM with NAFLD group were significantly lower than those in T2DM group(P＜0.01).(3) Regression analysis showed that homeostasis model assessment insulin resistance index (HOMA-IR),TG,and HDL-C levels were independent predicting factors for total adiponectin and HMW APN levels.TG and BMI were independent risk factors for T2DM complicated with NAFLD,while total adiponectin and HMW APN levels were the protective ones (OR =0.701,0.489,respectively).Conclusions Hypoadiponectinemia may partially play an important role in the development and progression of NAFLD in T2DM.