Objective To discuss the clinical manifestations and diagnosis of a patient with pulmonary alveolar proteinosis(PAP).Methods one case of PAP was analyzed and the recent literature was reviewed.Results PAP presented a protracted chronic clinical course,It was characterized by progressived Dyspnea.Typical CT scan showed diffused ground-grass opacities and thick interlobular septa in both lower fields,Typically with map changed and crazy paving patterns and milky effluent from bronchoalveolar lavage fluid(BALF).the microscopic characteristics of BALF from bronchoalveolar lavage of PAP indicated the alveolar space and terminal bronchioles almost completely filled with Periodic Acid Schiff(PAS)-positive surfactant.Conclusion The manifestations of PAP is not specific,image examinations and diagnostic bronchoalveolar lavege are very useful and lung lavage especially whole lung lavage is effective..