Medicinal plants play an important role in cure diseases such as diabetes mellitus. From these plants are Vinca rosea (Catharanthus roseus) and Sage (Salvia officinalis) which belong to Apocynaceae and Lamiaceae, respectively. The purpose of the present study is to examine the anti diabetic effect of streptozotocin (STZ) in deuced diabetic rats. Vinca rosea and Sage leaves were extracted and applied at 250 and 500 mg /kg b.w.         Results revealed that all plant extracts caused a reduction in serum glucose levels. The highest decrease was observed with Vinca rosea extract (500 mg/kg b.w.) from 445.00 to 128.61 (71.0%) after 30 days.        It was also clear that, investigated plant extracts improved the  triglyceride,  the levels of total lipid, HDL, LDL ,vLDL and cholesterol .       Further studies are necessary to prove the antidiabetic extracts and to evaluate their active components.