Abstract: Neochemoradiotherapy has been implemented in the multidisciplinary therapy for advanced rectal cancer. The patients with complete response after neothemoradiation could avoid surgical resection and thereafter might be free of surgical complications, as well as functional impairment. However, the preoperative evaluated clinical complete response is not equally to the pathologic complete response after surgery. The accurate methods to evaluate the status of complete response remained controversy. Based on the digital rectal examination and endoscopic observation, rectal MRI and endorectal ultrasound could verify the integrity of mucosa and the structural changes in rectal wall. These preoperative staging methods, as well as PET-CT and needle biopsy, had been widely used, but with a low sensitivity.