This study was conducted to investigate the safety and efficacy of an oriental herbal composition, Kamihonghwatang(KH-19), for the reduction of the side effects of chemotherapeutic drug. KH-19 prevented the reduction of white blood cells including lymphocytes, monocytes and eosinophiles in C57BL/6 mice injected with fluorouracil, a commonly used anticancer drug. KH-19 also prevented the reduction of cell densities in bone marrow and spleen of fluorouracil-injected mice. To evaluate the safety of KH-19, single-dose toxicity test was conducted using SD rats. No dead animal was found and the minimum lethal dose of KH-19 was more than 5000 mg/kg.