Actions for 48-hour homolgous passive cutaneous anaphylaxis (48-hr PCA) and chemical mediators were investigated in mice and rats. The hyaluronidase activity, which was used in the in vitro screening test of the antiallergic action, was significantly inhibited by Magnoiliae Flos, Achyranthis Radix, Forsythiae Fructus, Alpiniae Fructus, Anemarrhenae Rhizoma and Ponciri Fructus among twelve medicinal plants and tranilast as a comparative drug of the antiallergic action. In the mouse ear, 48-hr PCA was significantly inhibited by intraperitoneal (i.p.) pretreatment with Magnoliae Flos, Achyranthis Radix, Alpiniae Fructus, Anemarrhenae Rhizoma, Ponciri Fructus, Ledebouriellae Radix and tranilast. And also, the increment of vascular permeability induced by histamine or serotoin was inhibited significantly by i.p. pretreatment with Magnoliae Flos, Achyranthis Radix, Alpiniae Fructus, Anemarrheuae rhizoma, Zizyphi Fructus and tranilast. In the rat dorsal skin, the increment of vascular permeability induced by histamine or serotonin was significantly inhibited by i.p. pretreatment with Magnoliae Flos, Acyranthis Radix, Alpiniae Fructus, Anemarrhenae Rhizoma and tranilast. And also, the increment of vascular permeability induced by compound 48/80 or calcium ionophore A 23187 was significantly inhibited by i.p. pretreatment with Magnoliae Flos, Achyranthis Radix, Alpiniae Fructus, Amemarrhenae Rhizoma, Zizyphi Fructus, Ledebouriellae Radix, Lithospermi Radix and tranilast. These results suggest that each water extracts of Magnoliae Flos, Achyranthis Radix, Alpiniae Fructus and Anemarrhenae Rhizoma have especially antiallergic activities.