For locally advanced rectal cancer, multiple disciplinary team (MDT) has been the standard care. As a part of MDT, radiotherapy (RT) plays an important role in clinical practice. With mounting clinical evidence, RT is swifted from postoperative administration to preoperative. Compared to post-operative RT, pre-operative RT increased local control rate significantly, but not in DFS and OS. Two different preoperative RT models, short-course RT and long-course chemoradiotherapy demonstrated similar local control and long-term survival. However, a better tumor regression was observed in long-course CRT. In recent year, some small sample size studies, optimized the current pre-operative RT model, such as prolonging the interval between RT and surgery and adding consolidation chemotherapy (CT) in the interval, or adding induction CT before pre-operative RT. These optimizations decreased toxicities and increased treatment compliance, then improved the prognosis to a certain extent.