Abstract: The experimental diabetic model was established in SD rats by intraperitoneal injection of complete Freund’s adjuvant (CFA) and streptozocin (STZ,25 mg/kg) once a week for 3 weeks. The plasma levels of glucose (BG),insulin (Ins) ,C - peptide(C - P), glucagon (Glue) and somatostatin (SS) were measured by RIA at fast and lhour after sugar tolerance. The results showed that the levels of BG,Gluc and SS were significantly increased，While Ins and c - p were decreased at fast. One hour after sugar tolerance, the level of BG,Ins，c -p and SS was increased markably，while Glue was decreased. The results suggest that the functional interaction of the α,βD cells of the pancreas play an important role in diabetes mellitus.