Disclosed are an ABCG2 monoclonal antibody having the effects for resisting against tumors and for reversing drug resistance of the tumors, and uses thereof in novel tumor resisting drugs. Also disclosed is a new antigen sequence, used for inducing generation of a monoclonal antibody or a polyclonal antibody for the ABCG2. In addition, disclosed is a hybridoma for generating the ABCG2 monoclonal antibody having the effects for resisting against tumors and for reversing drug resistance of the tumors.
