 It is known that 20-60 of the rectal cancer patients treated with radical resection have the local recurrence. Therefore, chemo-radiotherapy before or after operation have been the standard treatment protocol in the rectal cancer patients to reduce the local recurrence, preserve more surrounding pelvic viscera, improve the prognosis and eventually quality of life. The preoperative chemo-radiotherapy was introduced by the German Rectal Cancer study, which compared pre- and postoperative chemo and radiotherapy. In this study, the authors reported that preoperative chemo-radiotherapy reduced local recurrent rate and 3 or 4 degree toxicity and improved the compliance for treatment. Since the introduction of chemo and radiotherapy in the treatment of rectal cancer, there have been numerous controversies on the guidelines or protocols of chemo-radiotherapy. In 1990, National Institute of Health NIH recommended postoperative chemo- radiotherapy to all the pT3 or pN1 rectal cancer patients at the consensus conference. In some studies, they reported that good clinical outcome and low local recurrence rate were obtained by only surgical treatment in the pT3N0 rectal cancer patients with favourable pathological characteristics. They also insisted that the effectiveness of postoperative chemo- radiotherapy was not evident. Gunderson, et al. retrospectively evaluated the five-year survival rate of the pT3N0 patients. They reported that the patients with surgery and chemotherapy showed the similar survival rate with the patients who underwent surgery and postoperative chemo-radiotherapy. National Cancer Data Base showed the similar report. However, there are some problems to apply theses results to the decision of preoperative therapeutic options. Moreover, some papers showed the low local recurrent rate less than 5 in the stage II without the supplement therapy, when the TME was precisely performed. All these results present the controversies on the radio-chemotherapy on all the T3N0 patients in terms of the clinical outcomes and the prognosis. In Korea, numerous clinical trials have been performed on the rectal cancer patients, however there has been no clinical study for preoperative chemo- radiotherapy in the T3N0 rectal cancer patients. In this reason, the protocols are different among institutions without unified standard treatment protocol. In this study, the authors compare the accuracy of diagnosis, the functional differences according to the preoperative chemo- radiotherapy, the local recurrent rate and survival rate between the two groups of T3N0 patients; one group with preoperative chemo-radiotherapy vs. the other without. In addition, the authors evaluate the advantage of the laparoscopic surgery, such as an extensive vision, so that laparoscopy can help rectal surgery as well as the surgical outcome. 