Cetuximab, a monoclonal antibody used to target the epidermal growth factor receptor(EGFR), was approved for refractory and metastatic colon cancer expressing EGFR, and the EGFR expression must be confirmed. But the EGFR expression may become false negative by immunohistochemistry. When we used a past operation specimen for a search in particular, a correct evaluation may be difficult for prolonged formalin fixation. We report a case successfully treated by cetuximab, who was diagnosed as EGFR-negative by the past operation specimen, but as EGFR-positive by the liver biopsy specimen. A 51- year old woman with multiple organ metastases, who had experienced failure with prior oxaliplatin, irinotecan(CPT-11), 5- FU and bevacizumab regimens, was administered cetuximab plus CPT-11 because it was EGFR-positive by liver biopsy, and the tumor was obviously reduced. It is useful to obtain another specimen such as by liver biopsy, when the EGFR expression is negative by a past operation specimen.