Objectives : This study was to assessment the toxicity of Sipjeondaebo-tang(Shiquan dabu-decoction) by micronucleus test. Methods : Sipjeondaebo-tang(Shiquan dabu-decoction) water-extract in vivo micronucleus test was performed using 7 weeks ICR mice. At 24 hours after with Sipjeondaebo-tang extract at the doses of 0, 500, 1000 and 2000 mg/kg/day by peritoneal route mice were sacrificed and bone marrow cells were prepared for smear slides. Results : As a result of counting the micronucleus polychromate erythrocyte of 2000 polychromate erythrocyte, all treatment groups did not show statistically significant increase than negative control group. and there was no clinical sign and body weight connected with injection of Sipjeondaebo-tang(Shiquan dabu-decoction) extract. Conclusions: It was concluded that Sipjeondaebo-tang extract did not induce micronucleus in the bone marrow cells of ICR mice