Most of rectal cancer patients were diagnosed at advanced or locally advanced stages due to the lack of specific relevant symptoms. With respect to the group of the local advanced rectal carcinoma (II/III stage), radiotherapy combined with total mesorectal excision (TME) surgery can significantly improve the local control rate and overall survival. Although the intensity modulated radiation therapy (IMRT) was widespreadly applied, the processes of IMRT from different institutions are not strictly identical. In this paper, we will introduce the instructions of standardization procedure of radiotherapy with rectal cancer in our center for guidance of clinical practice.