The present invention relates to humanized bispecific anti-HER2 antibodies that comprise one antigen binding site containing variable regions of heavy and light chain of trastuzumab, and another antigen binding site containing variable regions of heavy and light chain of pertuzumab. The bispecific anti-HER2 antibodies is effective for treating cancer, such as breast cancer, gastric cancer, or ovarian cancer. Preferred bispecific anti-HER antibodies of the present invention are afucosylated antibodies.
