Numerous studies have suggested that dietary flavonoids contribute to prevent cardiovascular disease. Onion contains many functional phytochemicals such as quercetin. The aim of this study was to examine whether onion peel extracts supplementation affect blood lipid profiles and blood coagulation in animal model. Total 48 Sprague-Dawley male rats at 5 weeks old were divided into 6 groups with different diets(C: control, HF: high fat diet, HFOE 0.01%: high fat+onion peel extract 0.01% diet, HFOE 0.02%, HFOE 0.05%, HFOE 0.1%) for 8 weeks. Onion peel extract supplementation significantly decreased serum levels of LDL-cholesterol and increased HDL-cholesterol, while total cholesterol and triglyceride levels were not affected. Hematological parameters(hematocrit, white blood cell, red blood cell, and platelet count) and blood coagulation parameters(prothrombin time, activated partial thromboplastin time, thrombin time, and fibrinogen) were not significantly different among 6 groups. However, activated partial thromboplastin time of HFOE 0.05% group was significantly longer than that of HF group. These results indicate that onion peel extract supplementation displays hypocholestrolemic effects but does not seem to have anti-coagulation effects in high fat fed SD rats.