A patient is a 35-year-old man. By a diagnosis of descending colon cancer, descending colon ablative operation and D1 lymph node dissection were performed on April 22, 2004. It was P3H0N1SE, Stage IV in perioperative findings. Abdominal CT showed peritoneal dissemination of 1.7 cm at the right under the abdominal wall wound and 1.2 cm in the rectovesical pouch on May 18, 2004. CPT-11 + TS-1 combination chemotherapy was started on June 22nd. In the five weeks of the combination chemotherapy, continuous infusion of CPT-11 (150 mg/body day 1 and 15) was twice administered, and oral administration of TS-1 (120 mg/body/day) was given for 3 weeks (day 1-21). Peritoneal dissemination disappeared after the two-course end, and we judged it as CR. Furthermore, we were certain that we obtained CR after the three course end. The adverse event was only neutropenia of grade 1. The fourth course was not administered, but recurrence has not been observed. Abdominal CT showed no recurrence on March 3, 2005 since the combination chemotherapy ended 6 months ago.