It has been suggested that Alternaria is the most prevalent fungal allergen based upon previous reports of airborne spore survey and allergy skin prick test. In order to observe the clinical features of Alternaria-sensitive asthmatic patients, and to evaluate a diagnostic value of allergy skin prick lest, serum specific IgE antibody, and bronchoprovocation test to Alternaria antigen, we performed allergy skin prick test with two sources of Alternaria antigens as well as 80 common inhalant and food allergens, and serum specific IgE antibody was determined by Ala-STAT(DPC, USA). To confirm bronchial sensitization, bronchoprovocation test with Alternaria alternata antigen from Allergophama (Germany) was performed on 15 asthmatic subjects sensitized to any of Alternaria spp. antigen, and compared between positive and negative responders. Eleven among 15 patients showed early (7) or dual (4) asthmatic responses. Four (36.4%) of 11 positive responders showed an positive response to one kind of Alternaria antigen on skin prick test. Four (36.3%) of them had a positive response to only Alternaria antigen with all negative responses to other fungal allergens. Seven (63.6%) of them showed positive responses to other fungal allergens such as Fusarium spp., Cladosporium spp., Aspergillus spp. All except one of 11 positive responders had high specific IgE antibody to Alternaria alternata on AlaSTAT. These results suggest that more than two sources of Alternaria spp. antigen should be used for screenig a causative fungal allergen. Determination of serum specific IgE can be helpful to complete the sensitivity of skin prick test in case of asthmatic patients sensitized to Alternaria antigen. Further studies will be needed to evaluate allergenic relationships with other fungal allergens appearing cocurrently on skin prick test.