Objective:　To study the relationship between lymphatic metastasis and extent of radical operation in advanced rectal cancer. Methods:　Seventy-six consecutive cases of rectal cancer subjected to D3 lymphadenectomy were analyzed retrospectively. Lymph nodes were classified as paratumoral regional and at the root of IMA, and for tumors below the peritoneal reflection, lymph nodes(LN) situated in the lateral ligament and mesorectum were examined as well. The metastatic rate was analyzed statistically. Results:　The rate of metastasis was 39.5%, 9.2% and 18.4% in the paratumoral, regional and the root of IMA respectively. The rate of LN metastasis in lesions with distal margin<2cm to the anus was 2.6%, while no metastasis was found in those with distal margin>2.0cm from the anus. The metastatic rate of LNs around the root of IMA was 10.5%. The metastatic rate of LNs in the lateral ligament and in the mesorectum for tumors below the peritoneal reflection were 11.8% and 12.5%. Conclusions:　In advanced rec-tal cancer below the peritoneal reflection, LNs tend to metastasize along the related blood vessels proximally, laterally and to the mesorectum. Extended lateral lymphadenectomy and total mesorectal excision(TME) should be included in cases below the peritoneal reflection.