We previously showed that a methanol extract of Paeoniae radix decreased total cholesterol level in rats with hyperlipidemia. In order to isolate the active ingredient(s), the methanol extract of Paeoniae radix was fractionated with chloroform/methanol(4:1) solution and isolate into soluble part and insoluble part of the the methanol extract. Above two parts were tested on the experimentally induced hypercholesterolemia in rats for the lowering effect of serum lipoprotein contents. Hyperlipidemia was induced on male Wistar rats by feeding high choleserol diet for 7 days. After oral administration of above samples for 4 weeks, serum lipid profile was verified on these rats by measuring total cholesterol, triglyceride, high density lipoprotein cholesterol and low density lipoprotein cholesterol. The chloroform/methanol(4:1) soluble part and insolule part showed lowering activity of total cholesterol level and triglyceride level at 4 week point significantly(p<0.01 and p<0.05) compare with the control group and the soluble part was more effective.