Lateral lymph node dissection is technique for reducing local recurrence rate after resection of rectal cancer. In this study, we will report a decade experience for lateral lymph node dissection of rectal cancer in 491 cases. Lateral lymph node metastases occurred in 15.4% of rectal cancer which was below peritoneal reflection and through muscularis propria into non-peritoneal. It is a problem that it has never been well designed study of lateral lymph node dissection for rectal cancer. On the other hand, TME has also contributed reducing local recurrence rate. But, distant margin for resection of rectal cancer is controversial.