Background: CM1 (centrocyte/-blast marker 1) is originally defined as a germinal center B cell marker. It is known that CM1 plays a critical role on B cell development in germinal center. In addition, we have found that CM1 is expressed on lymphoma cell lines, such as Raji, Ramos and IM-9. This means that CM1 might be served as a tumor marker as well. In the present study, we examined the expression of CM1 on the surface of the other tumors and the possibility of the development of tumor screening ELISA kit by using CM1. Methods: First, we have examined the expression of CM1 on stomach cancer and hepatoma, which are predominantly (discovered) occurred in Korean, by flow cytometry analysis. After purifying of CM1 antigen from Raji and Ramos, the optimal ELISA condition was determined. And then we compared the level of CM1 between normal individuals and cancer patients by ELISA. To decrease the non-specific binding of anti-CM1 mAb with serum components except CM1 and to enhance the diagnostic accuracy, albumin depletion spin column was used. Results: CM1 was highly expressed on stomach cancer and hepatoma cell lines. In addition, we have also confirmed the increased CM1 expression on cancer patients. The difference of CM1 expression between normal individuals and cancer patients were more clearly observed, after deletion of serum albumin by using albumin depletion spin column. Conclusion: Based on the results from this study, CM1 might be a useful molecule for the early diagnosis of cancer. In addition, further studies for the increase of ELISA sensitivity and appropriate albumin depletion methods should be needed.