Laparoscopic surgery has been increasingly performed in colon cancer patients; it has also been adapted for cases of advanced colorectal cancer. While performing an operation for rectosigmoid colon cancer, preservation of the left colic artery and prompt and accurate detection of the branch of the left colic artery from the inferior mesenteric artery is important. Detecting the left colon arterial bifurcation takes time, especially because of the presence of mesenteric fat, which is observed in many cases. In addition, in cases in which preoperative enhanced computed tomography (CT) cannot be performed, the surgery is sometimes performed without knowing the traveling vessel. As palpation is impossible, it is impossible to tactile running of the arteries as laparotomy in laparoscopic surgery. With endoscopic echo or Doppler echo, real-time identification of the blood vessels during surgery is possible without being invasive. It would be in laparoscopic surgery impossible palpation, and the combined use of intraoperative echo in ensuring the safety to be useful.