This study was conducted to investigate nitrite scavenging and Angiotensin Converting Enzyme (ACE) effects by antioxidant ingredient and the contents of phenolic compounds is isolated and purified from various sweetpotato cultivars. Various sweetpotato cultivars contained 4 phenol compounds including gallic acid, chlorogenic acid, gentisic acid and caffeic acid. The range of total phenol compound contents within cvs. Saengmi, Seonmi, Hongmi and Zami was at 23.0~48.8mg/100g and cv. Zami containing anthocyanins pigment whose total phenol compound content was at 48.8mg/100g was by far higher than the other cultivars. The assay of antioxidant activity using solvent fractionated extraction methods was investigated in various sweetpotato cultivars. Antioxidant activity of ethyl acetate (41.2~86.2%) was much higher than chloroform and butanol. Antioxidant activity from cvs. Sangmi, Seonmi, Hongmi, Shinyulmi, Zami and Sinchunmi was much higher than α-tocopherol well-known as natural antioxidant. Rancidity inhibitory effect about soybean oil of extracts fractionated by ethyl acetate from cvs. Saengmi, Seonmi, Hongmi and Zami was high considerably. Ethyl acetate layer among various solvent fractionated extraction had a good effect on nitrite scavenging rate but not had a effect on AEC inhibitory. Solvent of column chloromatography to isolate antioxidant contents from ethyl acetate layer was even better on 30% (MeOH) : 70% (Water) condition. There are 5 ingredients at HPLC chromatogram and antioxidant activity effect of individual ingredients was slightly better on Rt 11.9 and Rt 16.9 fraction.