Objective To study the effectiveness of local excision of low rectal tumor by Mason operation. Methods Twenty-our patients with low rectal tumor underwent Mason operation from 1997-2002 and their information was collected and studied. Results o recurrence was observed in the follow-p period from 5 months to 6 years after operation.Conclusion Mason operation for resection of tumor in low segment of rectum has the advantages of easy manipulation, minimal invasiveness and good exposure in operation.