Aim To investigate the effects of L-arginine on serum lipid, lipoprotein, lipid peroxide, and hemorhe-ology in petients with coronary heart diseasc and hy-perlipidema.Methods 4 tables (0. 25 g/tab )were given orally trice daily for 30 days in 30 patients with coronary heart disease and hyperlipemia. The serum lipid,lipoprotein apolipoprotein, lipid peroxide and hemorheology were meassured be fore and after treat-ment.Results L-arginine could significantly reduce serum total cholesterol, triglyceride, low density lipoprotein cholesterol and lipoprotein(a) levels (p<0. 01), but increase high density lipoprotein choles-terol level (p< 0.05). L-arginine could greatly lower lipid Peroxide level (p<0. 01 ),but increase su-Perokide dismutase activity(p<0. 01 ). L-arg-inine could decrease low shear of blood speific viscosi-ty, erythrocyte sedimentation rate (ESR),equation K value of ESR,aggregative index of red blood cell and plasma specific viscosity (p<0.01 ). An increase of plasma arginine level was companied with the above changes.Conclusions L-arginine releasing nitric oxide in vi-vo can suppress hyperlipemia and lipid Peroxide and improve helnorhfology in patitnts with coronary heart disease. Thus L-arginine may be used to treat coro-nary heart disease an byperliPemia.