AIM: To find out whether traditional Chinese medicine Angelicae Sinensis has direct suppressive effect on schistosome egg-induced granulomatous response. METHODS: The lung model of granuloma response was established by injecting living eggs of Schistosoma japonicum into the tail veins of eggs-sensitized mice then the preparation of Angelicae Sinensis were given intraperitoneally once a day for ten days. In vitro model of granulomatous reaction was set up by incubating dry schistosome eggs together with those splenocytes isolated from schistosome infected-mice or from the mice with pulmonary granuloma formation. Different doses of the preparation was, in the need of experiment, added to culture fluid. The sizes of granulomas formed surrounding single egg in lungs or the intensity of in vitro granulomatous responses were measured and observed. RESULTS: The average diameter of pulmonary granulomas in administered group was significantly smaller than that of the control ( P< 0.05). The increasing ratio of granuloma response in the administered group was also remarklely lower than that of the control ( P< 0.01). The intensity of in vitro granulomatous reaction (reaction index, RI) of in vivo administered group was lower than that of the control ( P< 0.01 or P< 0.05). After adding proper dosage of the preparation of Angelicae Sinensis to the culture fluid, RI of spleen cells from infected mice significantly decreased ( P< 0.01 or P< 0.05). CONCLUSION: The preparation of Angelicae Sinensis has suppressive effect on granulomatous reaction.