The seed of Vigna angularis (Ohwi) Ohwi & Ohashi (= Phaseolus angularis W. F. Wight, Leguminosae) is one of well-known folk foodstuffs in Korea, China and Japan. In the course of screening for antioxidants from natural plants in Korea by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) a methanol extract of the seeds of V. angularis were found to show a potent antioxidant activity. And the ethyl acetate soluble fraction of V. angularis (VAEA) showed the most potent DPPH radical scavenging and superoxide quenching activities. To reveal the effect of antioxidant activities of VAEA, we tested the thermal and oxidative stress tolerances, activities of SOD and catalase, and intracellular ROS level in Caenorhabditis elegans. Consequently, VAEA-fed worms lived longer than control worms under the thermal and oxidative stress conditions. And VAEA elevated SOD and catalase activities of worms, and reduced intracellular ROS accumulation in a dose-dependent manner.