Leaves of Eriobotrya japonica Lindl. (Rosaceae) (LEJL) have been used as traditional medicines for inflammatory diseases and chronic bronchitis. However, its effect on mast cell-mediated anaphylactic reaction is not known. The anaphylactic allergic reaction is involved in many allergic diseases such as asthma and allergic rhinitis. In this report, we investigate the effect of LEJL on the anaphylactic allergic reaction and studied its possible mechanisms of action. LEJL inhibited compound 48/80-induced systemic anaphylactic reactions and serum histamine release in mice. LEJL dose-dependently decreased the IgE-mediated passive cutaneous anaphylaxis and histamine release from mast cells. Furthermore, LEJL decreased the production of tumor necrosis factor-alpha in phorbol 12-myristate 13-acetate and A23187-stimulated human mast cells. These findings provide evidence that LEJL could be a candidate as an anti-allergic agent.