Purpose: Assessing the effects of preoperative radiochemotherapy with Capecitabine in low locally advanced rectal cancer. Patients and Methods: intervention studies, clinical trial one sample no control in 87 advanced rectal cancer patients treated by preoperative radiochemotherapy at The Nuclear Medicine and Oncology Center, Bach Mai Hospital and 4th radiation Department, K Hospital from 6/2009 to 12/2012. Results: 100 percent patients had functional response. Tumor volume with rectal circumference decreased after treatment. Before treatment: 52.9 percent of the patients with entire circumferent tumors dropped to 16.1 percent. 2.3 percent of patients with non-palpable tumors after treatment. 40.2 percent patients with CEA levels Sng/ml before treatment in which 91.4 percent patients had reduced CEA levels. 90.8 percent patients achieved a response after treatment and 9.2 percent patients complete response. 79.3 percent patients underwent surgery in which 67.8 percent patients with radical surgery, 12.6 percent patients underwent anal sphincter preserving surgery. Conclusion: Radiation therapy combined capecitabine before surgery was effective for low locally advanced rectal cancer, improved functional symptoms, downstage, increased the rate of radical and anal sphincter preserving surgery.