The purpose of this research was to investigate the effect of Yonggak-san (YGS) on the anti-allergic reaction in vivo and in vitro. Administration of YGS(500 mg/kg) enhanced hemaggutination(HA)titer against SRBC. On the while, YGS inhibited hyaluronidase activity in vitro and passive cutaneous anaphylaxis reaction, lethal anaphylaxis and mortality induced by compound 48/80 in mice, YGS decreased Arthus reaction, acute hind paw edema induced by histamine. But YGS did not affect delayed type hypersensitivity induced by SRBC. These results suggest that YGS have anti-allergic action