The separation of cells by magnetic beads method is based on the fact that the cell surface antigen can be combined with the specific monoclonal antibody connected with the magnetic beads. In the external magnetic field, the cells connected with the magnetic beads by the antibody are adsorbed and remain in the magnetic field. The cells without such surface antigen have no magnetism because they cannot be combined with the specific monoclonal antibody connected with the magnetic beads, so they do not stay in the magnetic field, so that the cells can be separated.