Abstract: Objective This paper study the clinical pathology、fiberbronchoscope、immunohistochemistry characterstic of small cell cancer of lung which amount to 218 cases.Among them there are 186 cases of male,and female 32 cases,the age of patients are from 29 years to 74 years. Methods analyse the fiberbronchoscope and pathological character,and select 80 case to accomplish the immunohistochemical study.Reaults the fiberbronchoscope show irregular nodular knurl and cavity is most common.eighty immunochemical stain result indicate:CK 64、EMA 74、 NSE 72、5-HT 56 cases are demonstrated positive reaction,indicate that they are differentiated toward epithelial and neuroendocrine Conclusion small cell carcinoma of lung is differentiated toward epithelial and neuroendocrine,this prove the small cell cancer of lung is generated from multi potent stem cell