Abstract:In this study ,castor seeds were processed by one of the traditional Chinese methods,LD50 was measured and tu-mor inhition tests in nude mice bearing human pulmonary carcinonia were conducted.The results showed that the pro-cessing methed was able to lower the toxicity of castor seeds and niaintain their antitumor effect,thus providing an ex-perimental basis for oral administration of castor seLeds in the therapy of pulmonary carcinoma.