The hypoglycaemic activity and biochemical effects of cataranthusroseus with diabenese in normal and diabetic rats were compared. Ethanollic extract of C. roseus were screened for their phytochemical constituents using standard methods. Biochemical effects were evaluated on alloxan induced diabetic rat (32) assigned into four study groups of eight rats each Group 1 (control) received diabinse (14.28mg/kg). C roseus (400mg/kg) all in 30% ethanol. At the end of 21 day administration period blood serum was obtained from sacrificed animals and biochemical indices of toxicity (lipid profile, aminotransferases activity, serum protein, urea and albumin.