Abstract: D- isoascorbyl palmitate( IP) was synthesized with lipase- catalyzed method and its antioxidant activity was evaluated in model systems and food oil systems compared with that of BHT( butylated hydroxytoluene),BHA( butylated hydroxyanisole) and TBHQ( tert- butyl hydroquinone). The results showed that IP had the higher scavenging effect on hydroxyl radical and reducing power compared with other tested antioxidants while it had slight lower superoxide anion and DPPH· scavenging powers than those of TBHQ.In the grease accelerated oxidation,IP showed significantly inhibited effect on oil rancidity.