Objective:To determine the expression of AC133 and EpCAM in human pulmonary adenocarcinoma by dual immunofluorescent labeling technique and to isolate AC133+EpCAM+ cells by flow cytometry,so as to provide a basis for further investigation of human pulmonary adenocarcinoma stem cells.Methods:The human lung adenocarcinoma tissues were obtained and subjected to cryosection and dual immunofluorescent staining.AC133+EpCAM+cells in human pulmonary adenocarcinoma were identified by using laser confocal microscopy.The fresh adenocarcinoma tissues were prepared into single cell suspension with the collagen and red blood cell removed.AC133 and EpCAM were used to label cells and the AC133+EpCAM+cells were isolated by flow cytometry.Results:AC133+EpCAM+ cells were found in human pulmonary adenocarcinoma and they could be isolated by flow cytometry.Conclusion:The existence of AC133+EpCAM+ cells has been confirmed in the lung adenocarcinoma tissues; the double positive cells can be isolated by flow cytometry,which provides a basis for further investigation of lung cancer stem cells.