The effects of Ephedrae herba on cellular and humoral immune responses were investigated in mice. Group A and B of mice received intraperitoneal injection of methanol extracts, ether fraction(E), petroleum ether fraction(PE), ethyl acetate fraction(EA) and water fraction(W) for 5 days or 10 days before sensitization. The other group received i.p. injection of ephedrine (Ep) or pseudoephedrine $({psi};Ep)$ for 1 day prior to sensitization. The change of body and spleen weights showed a tendency of decreasing but that of thymus showed increasing. Ear swelling was maximum at 48 hours after challenge and was significantly decreased in the groups treated with EA, W, Ep, and ${psi};Ep$. HA titer was enhanced in EA, W and EP treated groups, HE titer being significantly decreased.