Objective: To assess the clinical value of transanal drainage in treatment of anastomotic leakage after anus-preserving resection for mid/lower rectal cancer. Methods: The clinical data of 21 patients developing anastomotic leakage after anus-preserving resection for mid/lower rectal cancer from January 2010 to October 2013 were retrospectively analyzed. Of the patients, 9 cases received transanal drainage (observational group), and 12 cases underwent abdominal drainage tube irrigation only (control group), and the associated clinical parameters were compared between the two groups. Results: All patients in the two groups recovered and were discharged from the hospital. None of the patients in observational group required a colostomy, but 2 cases in control group underwent colostomy attributed to conservative treatment failure, however, the difference did not reach a statistical significance (P=0.122). The difference in total length of hospital stay between the two groups had no statistical significance (P=0.061), but the length of post-fistula hospital stay and hospitalization cost in observational group were lower than those in control group, and the differences had statistical significance (P=0.012, P=0.031). Follow-up was conducted for 2 months to 3 years, and no statistical difference was noted between the two groups in incidence of postoperative symptoms such as constipation, diarrhea, anal discomfort (P=0.066). Conclusion: Transanal drainage can be used as an important method for treatment of anastomotic leakage after anus-preserving resection for mid/lower rectal cancer, which has the advantages of shortening the length of post-fistula hospital stay, reducing hospitalization cost, and high patients’ acceptance.