The aim of present study--comparative characteristic of captopril and of losartan action on the oxidative metabolism in experimental hyperlipidemia. Experiments carried out on rabbits,which were divided into three groups(ten animal in each group) and orally receiving during 45 days: I control group (cholesterol 500mg/kg + methylthiouracil 100mg/kg, II group-captopril 5 mg/kg + cholesterol 500mg/kg + methylthiouracil 100mg/kg, III group-losartan 8mg/kg + cholesterol-500mg/kg + methylthiouracil 100mg/kg. Activity of superoxide dismutase, catalase, level of malonic dialdehyde, osmotic resistance of erythrocytes and resistanse of LDL to oxidation and concentration of nitric oxide in the blood have been evaluated . The administration of captopril and losartan in experimental hyperlipidemia eqivalently increased activity of SOD and catalase, osmotic resistance of erythrocytes and resistanse of LDL to oxidation, whereas decreased content of malonic dialdehyde compared to the control group . Captopril was more effective than losartan in preserving of nitric oxide. We conclude that captopril and losartan inhibited oxidative stress, which are probably associated with the inhibition of angiotensin 11. Captopril and losartan are safely used in patients during cardio-vascular disease with dyslipidemia.