Colorectal cancer is the third most commonly diagnosed cancer in the world, nearly all patients diagnosed with this cancer die from it. Antibodies are glycoprotein molecules, which can efficiently recognize and eliminate specific pathogenic and disease antigens. Antibody researches for the last several decades have demonstrated the potential of therapeutic antibodies to fight cancer. Monoclonal antibody (mAb) CO17-1A recognizes the tumor-associated antigen GA733-2, a cell surface glycoprotein highly expressed in colorectal carcinoma cell, which is applicable for preventing and curing colorectal cancer. We have currently established baculovirus insect cell expression system to produce anti-colorectal cancer mAb CO17-1A. In this study, mAb CO17-1A was expressed in the transgenic insect cell line SWT4, which has humanized glycosylation processing pathway. Immunoblot confirmed that mAb CO17-1A properly expressed in SWT4. mAb CO17-1A was purified using protein G affinity column. In addition, Maldi-TOF verified that the mAb fused to KDEL, ER retention signal had high mannose type of glycan structure whereas the mAb without KDEL had partially humanized glycan structure. These results suggest that the insect cell expression system with the SWT4 possibly can be used as a useful alternative way to produce full-size mAb with humanized glycan structures for cancer immunotherapy.