To search of more selective vasculogenic relaxation activity, the antioxidant activity of silkworm male pupae was determined by measuring its radical scavenging effect on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and anticoagulant activity of them was measured clotting time in both activated partial thromboplastin time (aPTT). Because, most of cGMP-enhancing agent such as, sildenafil, promotes thrombin-induced platelet aggregation, developed unexplained thrombic conditions including heart attack. To search more suitable and safe drug for vasculogenic relaxation, we purified silkworm pupae male extract. The ethyl acetate extract of silkworm male pupae showed strong scavenging activity in both DPPH and aPTT anticoagulant activity. The antioxidant activity potential of the individual fraction was in order of ethyl acetate > n-butanol > chloroform > n-hexane. The ethyl acetate soluble fraction exhibiting strong anti-oxidant and anticoagulant activity was further purified by repeated silica gel and Sephadex LH-20 column chromatography. Cholesterol was isolated as one of the active principles from ethyl acetate fraction, together with, minor portion, ${eta}-sitosterol$.