To evaluate the hypoglycemic effect of propolis, streptozotocin (STZ) induced diabetic rats were divided into 4 groups such as, diabetic control group, low dose of propolis (0.1 ml) group, medium dose of propolis (0.3 ml) group and high dose of propolis (0.9 ml) group and feeded with propolis extracts for 30 days. After experiment, oral glucose tolerance test (Oral GTT) was carried, and 16 hours fasting blood sugar levels, body weights, blood lipid levels were measured. Finally, pancreatic histopathological study was performed. In conclusion, the propolis is effective to the treatment diabetes due to the reduction of the blood sugar level and the regeneration of the damaged $eta$-cells shown in streptozotocininduced diabetic rats.