Abstract: Anastomotic leakage is one of the most serious complications after anus preserving operation in rectal cancer patients. Risk factors include patient-related factors, therapy-related factors, anesthesia and surgical-related factors. The main prevention measures include intraoperative examination of anastomosis, assurance of blood supply of anastomotic intestine, abdominal/pelvic drainage, protective stoma and transanal drainage. Identify risk factors and decrease the occurrence of anastomotic leakage are important for the improvement of patient outcomes.