One of the most common disorders of the endocrine system is diabetes mellitus. This disease is associated with dyslipidemia. Adiponectin is a protein hormone that secreted by adipocytes and has an important role in regulating of glucose and fatty acid metabolic pathways. This study was designed to investigate the changes in serum level of adiponectin in diabetic rats treated with hydroalcoholic extracts of three medicinal plants; jujube (Ziziphus jujuba), barberry (Berberis vulgaris) and saffron (Crocus sativus) in comparison with quercetin. Streptozotocin -induced diabetic male rats were gavaged with specified doses of the extracts (25 and 100mg/kg) for two weeks. At the end of treatment period, fasting blood specimens were collected. The levels of adiponectin, fasting blood sugar (FBS), total Cholesterol, triglycerides, HDL-C and LDL-C were measured. Statistical analysis showed that serum levels of triglyceride and VLDL decreased significantly (P<0.05) in all treated groups. FBS level in all treated groups, decreased significantly and reach to normoglycemic level (P<0.05). Except Jujube, other plant extracts had no effect on cholesterol. Jujube in two doses (25 and 100mg/kg) could increased significantly HDL-C (P<0.05) with no effect on total cholesterol and LDL-C. Serum adiponectin level increased in all treated groups. These beneficial effects of C. sativus, B. vulgaris and Z. jujube extracts and quercetin in diabetic rats may be associated with increase in adiponectin level.