K.alvarezii is a macro algae that claimed to have beneficial effect on reducing risk of cardiovascular disease. The present study investigated the effects of K. alvarezii on the histology of the heart in hypertensive and hypercholesterolemic induced rats. Thirty male Sprague-Dawley rats were divided into 5 groups: normal, negative control, positive control (Captopril 30mg/kg + Simvastatin 2 mg/kg), 5% and 10% K. alvarezii. All groups were fed with NaCl-high fat diet (NaCl-HFD) for 6 weeks except the normal group and treated for 4 weeks after the induction period. The body weight, blood pressure and total cholesterol were measured on week 0, 6 and 10. Body weight, blood pressure and total cholesterol was significantly increased after induction period compared to normal group (p