This present study was aimed to investigate the antidiabetic and antihyperlipidemic activities of methanolic leaf extract (LE) of Stephania japonica alone and in combination with metformin in alloxan induced diabetic rats. Primarily acute toxicity study and oral glucose tolerance test were performed. Diabetes was confirmed after 12 days of single intraperitoneal injection of alloxan (120 mg/kg BW) in albino male rats. Rats were divided into six groups'; normal control (Group I) and diabetic induced groups as (Group II, effect and hence could be suggested as a potential therapeutic agent for diabetic treatment.