Eight Brown Norway rats were immunized twice at days 0 and 13 by intraperitneal injections of 10 micrograms Cry j I, one of major allergen to Japanese cedar pollinosis, mixed with 4.5 mg aluminium hydroxide gel. Serum level of Anti-Cry j I IgE antibody was detected by the method of ELISA. Mean value of serum levels of specific IgE to Cry j I in the sensitized rats was significantly higher than that in the non-sensitized five rats (p