Objective  To isolate and identify the subgroups of tumor stemlike cells with a highly metastatic potential from Lewis lung cancer (LLC) cell line.   Methods  The ratio of Sca-1 and CXCR4 cells with dual-color immunofluorescent staining in LLC was determined by flow cytometry

and their expression in lung tissue of mice was detected by laser confocal microscopy. CXCR4

+

cells were used as a magnetic head in isolation of surface markers on the cells as well as in detection of cell activity before and after isolation. Biologic

al behaviors of subgroups of positive CXCR4 cells were observed and analyzed.   Results  The ratio of Sca-1 and CXCR4

+

cells in LLC was 0.1%

and the rate of positive CXCR4

+

cells in LLC was 0.18%. Dual-color immunofluorescence-stained cells were observed in mouse lung tissues. The cell activity was (95.58±0.87)% and (94.96±0.76)% respectively

before and after isolation  (P0.05). Tumor formation was found in subgroups of positive CXCR4 cells (7×10

3

). Negative and positive CXCR cells were inoculated into 3 mice respectively at the concentration of 5×10

5

and 2×10

4

cells. No metastasis occurred in the former group. However

lung metastasis was found in 2 mice and ear metastasis was observed in 1mouse of the latter group.   Conclusion  Subgroups of positive CXCR4 cells in LLC are characterized by certain properties of cancer metastatic stem cells and have the ability to renew themselves and metabolize.