There are chemotherapy methods applied before operation, before and after operation, or after operation for metastatic colorectal cancer. But the correct times and periods, etc., for their administration have not been obvious. We perform maximum preoperative chemotherapy to control micrometastases, and afterwards surgically remove the metastatic lesions[including radiofrequency ablation(RFA)]. Complications after operation and the severity of pathological liver damage etc., were investigated by comparing 14 patients who received maximum preoperative chemotherapy(group A), with 4 patients for whom 6 courses of FOLFOX+bevacizumab(BV)therapy(group B)were planned. ICG15 before liver resection and bleeding during liver resection were not significantly different(p=0. 26 and p=0. 60, respectively). No severe complication after operation was seen and pathological liver damage was minor in both groups. No interference of maximum preoperative chemotherapy with BV to metastatic colorectal cancer was suggested from the point of view of complications after operation and the severity of pathological liver damage. Further investigation with many more patients is necessary.