The effects of Shosaiko-to and its constituent crude drugs on the inflammatory responses were investigated in rats. The intraperitoneal administration of Shosaiko-to produced a dose-dependent inhibitory effect on the carrageenin-induced paw edema in rats. The suppression of the carrageenin-induced paw edema by Shosaiko-to decreased significantly in adrenalectomized rats. The elevations of serum and adrenal corticosterone levels were observed in rats treated with Shosaiko-to. Bupleuri Radix, Scutellariae Radix, Zingiberis Rhizoma and Ginseng Radix at an intraperitoneal dose of 100 mg/kg suppressed significantly carrageenin-induced paw edema, but Glycyrrhizae Radix, Zizyphi Inermi Fructus and Pinelliae Tuber did not. The active principles of Shosaiko-to producing anti-inflammatory effects were absorbed on Amberlite XAD-2 and eluted with ethanol. These results suggest that Shosaiko-to suppressed the carrageenin paw edema and that the anti-inflammatory action was partly due to an increase in adrenal function.