Rectal cancer is one of the most common malignant tumors. In China, rectal cancer has been the third most frequently diagnosed cancer and the fifth leading cause of cancer death, with changes of residents’ lifestyle factors and diets. The best treatment for rectal cancer depends on many factors. Multidisciplinary Treatment has become the basis for improving the therapeutic effect, in which radiology is increasingly necessary for treating patients with rectal cancer. For patients who have extensive, fixed, bulky tumors or obvious nodal disease, radiotherapy and chemotherapy combined with surgery has emerged as the standard of care. For patients with metastatic disease, the reasonable combination of local and systemic therapy might be an alternative. Improvements in imaging, pathological diagnosis and radiation techniques provide a solid foundation for promoting the level of clinical practice in rectal cancer. High-quality magnetic resonance imaging distinguishing risk stratification, molecular markers predicting therapeutic effect and prognosis, magnetic resonance imaging in delineating target volumes drawn, intensity-modulated radiation therapy, and image-guides radiation therapy for precision treatment delivery are all being widely applied in multiple centers. Furthermore, as the role of targeted therapy and immune therapy has become increasingly prominent, the attempt of combined radiotherapy is also ongoing. In view of the characteristics and current situation of diagnosis and treatment of rectal cancer in China, the guidelines will present the basis and reference for combined treatment and standardized treatments. Meanwhile, there may be continuous new advances in clinical practice, and that will be a new basis to update the guidelines, directly benefiting all rectal cancer patients and facilitating discipline developments.