We report a case of bird-related chronic hypersensitivity pneuminitis exhibiting the fluctuation of serum markers for interstitial lung disease along with the changes in life environment. A 65-year-old man had had an abnormal chest radiograph for 2 years and had complained of a non-productive cough. He had had 30 parakeets 20 years previously and had used feather products for 15 years. In autumn and early winter wild birds had visited persimmons trees in the neighboring garden. Antibodies to bird-related antigens in the broncho-alveolar lavage fluids and sera were positive and the thoracoscopic lung biopsy specimens histologically revealed airway-centered fibrosis. We then determined he was having bird-related chronic hypersensitivity pneumonitis. After avoidance of feather products, all of serum SP-A, SP-D and KL-6 decreased. But three markers elevated and radiographic findings worsened accompanied with the increase of visiting wild birds in next autumn. After pruning persimmon trees and starting corticosteroid with cyclosporine, disease activity gradually improved.