【Abstract】 Objective To investigate the clinical characteristics of patients with allergic pneumonia diagnosed by different diagnostic methods and analyze the difference between pathological diagnosis and clinical diagnosis. Methods The clinical data of 87 patients with allergic pneumonia in our hospital from December 2014 to January 2010 were retrospectively analyzed. The clinical characteristics of the two groups were compared according to the different diagnostic methods for pathological diagnosis group (n=41) and clinical diagnosis group (n=46).Results In 87 patients, the clinical manifestations were cough, shortness of breath (9310%) (7701%), diffuse pulmonary lesions (3333%), double lung pleura (2529%), type of disease with ground glass opacity (6552%), the manifestation of shadow grid (4483%), exposed to contact the animal protein factor (4368%), chemicals (3563%), previously misdiagnosed as pulmonary infection (2184%) and pulmonary tuberculosis (1379%). The number of lymphocytes in patients with ＞20% CD4/CD8＜09 of history less than 6 months was significantly lower than the rate of 6~12 months duration and duration of more than 12 months patients (P＜005). The clinical diagnosis of patients with acute, subacute group was significantly higher than the proportion of pathological diagnosis group (P＜005). 2 patients were exposed to factors have obvious difference (P＜005).Conclusion The clinical manifestations of allergic pneumonia are complicated, and the clinical manifestations of different diagnostic methods are significantly different. Some typical cases could be diagnosed by bronchoalveolar lavage fluid (BALF).