Cinnamon is a small evergreen tree 10-15 meters tall, belongs to the family Lauracae. The leaves are ovate-oblong in shape, 7-18 Cm long, the flowers which are arranged in panicles, have greenish color and distinct odor. The fruit is a purple one centiberry containing a single seed. Cinnamon are widely used as spice and flavoring agent and can be clinically used in treatment of certain diseases such as type 2 diabetes mellitus. Cinnamon extract has blood glucose lowering effect in patients with type 2 diabetes. This study tested the effect of cinnamon extract on D- glucose induced hyperglycemias which showed significant reduction in plasma glucose level. Chronic hyperglycemia model induced by a single intraperitoneal injection of streptozotocin, the extract showed marked decrease in blood glucose level.