From our previous report, the water extract of Pulsatilla koreana root was found to have potent anti-inflammatory and analgesic actions in intravenous administration in animals. Among chloroform, ethyl acetate, butanol and water fractions which were obtained through successive fractionation of the extract, only the water fraction was found to have the antiinflammatory and analgesic actions. The fraction did not affect normal body temperature at the effective doses in mice and showed low acute toxicity of which $LD_{50}$ was less than 500 mg/kg i.v. in mice. It is interesting that its anti-inflammatory action might be attributed in part to inhibition of cyclooxygenase-1 and -2.