A case of allergic bronchopulmonar aspergillosis is presented for the first time in Korea. The patient was 41 yearwld male admitted to Seoul National University Hospital due to aggravated dyspnea and sputum production. He had asthma since 6 years before which had been controUed by oral and aensolized bronchodilators. Past medical history was not remarkable except pulmonary tuberculosis at 15 years of age. His mother, one brother and one sister had the histories of asthma. Physical examination revealed fever (38.2C), tachypnea (28/min), tachycardia (102/min) and expiratory wheezes on the entire lung fields. The FVC was 1.20L, FEV, 0.43 L, PO, 72 mmHg, PCO, 51 mmHg. Peripheral blood showed leukocytosis (118,000/mm) with eosinophilia (1,276/mm). Total serum IgE level was 1,620 u/ml and specific IgE to A.f. was detected by RAST. Precipitating antibody against. A.f. was also identified noted. Sputum culture was positive for A.f. Intradermal skin test to A.f. showed dual reactions. Chest X-rays showed changing patterns of pulmonary infiltrates despite of antibiotic treatment. After administration of corticosteroid (60 mg of prednisolone per day), all symptoms and physical signs improved, eosinophil count and serum IgE decreased, and pulmonary infiltrates disappeared.