Abstract: cases of inflammatory pseudotumors in the lung are reported. There were 21 males and 14 females. Their ages range from 21 to 65 years. The mass shadows varying from 2 to 12cm in diameter. They can be divided into 4 types according to the predorminant cells and structure: pseudopapilloma (17cases, 48.5% ), histiocyte type (12 cases, 34.3%), plasme granuloma (4 cases, 11.5% )and pseudolymphoma (2 cases, 5.7% ). It was analyzed carefully to bring about better understanding of the natural of such lesions and relationship among pathologyical changes, clinical manifeslations and rediograhic pictures, thereby, to facilitate their dagnosis.