Abstract: Objective 　To study micro2vessel dist ribution in rectal cancer and it s distal mucosa and to ex2 plore the required distal margin of radical surgery for rectal cancer in molecular pathologic level. Methods 　MVD (Micro2vessel Density) in rectal cancer and rectal distal tissue portion were detected by immuno2 histochemical stain and semi2determination techniques. Results 　MVD in rectal cancer was significantly higher than that in distal mucosa to cancer margin. MVD was decreased in distal mucosa along the anal direction. But only in less than 1. 0cm distal rectal tissue was significantly abnormal. Conclusion 　MVD in distal mucosa to cancer margin might be a relatively independent parameter to predict resection margin. From molecular pathology point of view, the length of distal resection margin to rectal cancer should be longer than 1. 0 cm.