Skin tests, serum total IgE levels, specific IgE antibodies against each allergen, bronchial reactions provoked by allergens and histamine release from basophils are well known as prameters of immediate allergic reactions. The incidence of positive immediate skin reaction to allergens such as house dust, ragweed, Aspergillus Alternaria, Cladosporium and Broncasma decreased with aging. On the other hand, the incidence of positive skin reaction to Candida albicans was higher in cases between the age of 41 and 50 and cases over the age of 61 compared to that in the other groups classified by age. Serum IgE levels was highest in cases aged between 0 and 30. The levels of serum IgE decreased with aging. The incidence of positive RAST scores (more than 2+) and positive bronchial reaction to house dust were highest in cases between 0 and 30, and decreased with aging. However, the positive ratio of these tests against C. albicans were highest in cases between 41 and 50. The degree of histamine release from basophils of asthmatics induced by anti-IgE was consistently high without any correlation to aging when their serum IgE levels were more than 501 IU/ml. In the cases with serum IgE levels of less than 300 IU/ml, basophil reactivity to anti-IgE decreasd with aging. Basophil reactivity to house dust was generally dependent on the levels of specific IgE antibodies against the allergen. Although basophil reactivity to C. albicans was also high in cases with positive RAST scores, some cases with a RAST score of 0+ or 1+ showed high or moderate basophil reactivity. Moderate or high reactivity of basophils was frequently observed in cases between 41 and 50 and cases over age 61.