The bioactive monacolin K found in red mold rice (RMR) is identical in structure to lovastatin, and has the effect of lowering the cholesterol level in human blood. Statins not only lower atherosclerosis caused by thrombus, but also reduce the death rate from coronary artery disease. This study was designed to evaluate the effects of?Monascus purpureus?NTU 803 fermented-RMR on blood coagulation and anticoagulation factors in hyperlipidemic rats. Rats were fed a high-lipid diet for 8?weeks to induce hyperlipidemia and fed various doses of RMR. The results showed that RMR prolonged the bleeding time of the rats, inhibited platelet coagulation, lowered the fibrinogen content in the blood, increased the antithrombin III and protein C content in the blood, and reduced lipid plaque in the aorta. RMR was effective for preventing the formation of thrombus and reducing the occurrence of atherosclerosis.