Abstract: Polysaccharides were extracted from Radix Scrophulariae by ultrasonic-assisted hot water as liquid and purified through degrease, liminating pigment, removing propeins and alcohol-precipitation.With the same concentration of ascorbic acid as the control, the antioxidant activities of polysaccharides were investigated by testing scavenging effect of ·OH, O₂～-·, NO₂～-and against the peroxidation of oils and fats.The results showed that Radix Scrophulariae polysaccharides exhibited a strong ability to remove ·OH, O₂～-·, NO₂～-and good inhibitory effect on peroxidation of oils and fats.The ability to remove ·OH, O₂～-· and NO₂～-was increased with concentration of Radix Scrophulariae polysaccharides increasing.Furthermore, Radix Scrophulariae polysaccharides possessed a stronger inhibitory effect on peroxidation of oils than ascorbic acid.