To develop a material for functional food, the fraction Ⅰ,II and Ⅲ of onion extract were separated by Sephadex LH-20 column. The revealed purification levels of each fraction were 5.2%-6.5%, 12.2%-14.5% and 82.6%-86.7%, respectively. A functional activity test was performed with fraction Ⅲ. The ACE inhibition activity was about 50% at 5mg and about 80% at 10mg. The XOase inhibition activity of Korean Changnyong Daego was 84%, which was the highest. At the experiment of tyrosinase inhibition was detected 21-36% at 10mg. The cholesterol dose in mice blood was as low as low as 79$pm$5(mg/100 mL) after the intake of fraction Ⅲ. Cholestrol dose in liver was decreased to below 50%. The results show that Sephadex LH-20 column method was very useful as a fraction method for the development of functional food material nsing onions.