This study was carried out to elucidate the antiinflammatory effect of 50% ethanol extract obtained from the fruit of Trichosanthes kirilowii Maxm, and its effective parts. The cut dried fruit was separated into the whole fruit, seeds and remaining parts, and each part was extracted with 50% ethanol. The antiinflammatory activity of these extracts was investigated on acetic acid-induced vascular permeability in mice, carrageenin-induced edema and cotton pellet-induced granuloma formation in rats, as well as writhing symptoms in mice. The whole fruit and seed extractions showed an antiinflammatory activity and analgesic activity, but the other part did not when given perorally. These results suggest that the antiinflammatory effect and analgesic effect induced by ethanol extract of the fruit of T. kirilowii may be due to the seeds contained in the fruit.