The rhizome of Ligusticum chuanxiong Hort. (LC), also known as chuanxiong, is a very common herb widely used to treat cardiovascular and cerebrovascular diseases. It is also used as a major ingredient in soups for regular consumption to promote good health. To study the protective effect of LC ethanolic extract (LCEE, 600 mg per kg per day, p.o.) on the integrity of the vascular system, ovariectomized (OVX) rats were fed with a high-fat diet (HFD) plus LCEE for 12 weeks. The animal model was used to mimic the dyslipidemic condition seen in postmenopausal women. LCEE was found significantly to reduce the body weight gain, improve serum lipid profiles (by lowering total cholesterol and low density lipoprotein cholesterol but raising high density lipoprotein cholesterol) and protect vascular endothelium in the HFD-fed OVX rats. It is postulated that LCEE could exert its vascular protective effect through multiple targets by (1) improving serum lipid profiles to reduce the detrimental effects of cholesterol; (2) reducing the ROS level in the body via enhancing the hepatic anti-oxidative activity or antioxidant level to scavenge the reactive oxygen species generated in the postmenopausal hypercholesterolemic condition; (3) stimulating eNOS-derived nitric oxide production; (4) counteracting the up-regulation of inflammatory cytokine (TNF-alpha,, VCAM-1 and ICAM-1) expressions so as to reduce endothelium damage. ; Department of Applied Biology and Chemical Technology