Radiation-induced dermatitis is one of the most prevalent complications in patients undergoing cancer radiotherapy and poses a significant challenge to cancer therapy. The symptoms include erythema, dry desquamation, and moist desquamation, which are frequently observed in patients with breast, head and neck, anal, and vulvar cancers. Early skin reactions typically manifest within 2-4 weeks following the initiation of radiotherapy. In severe cases, acute dermatitis can cause radiotherapy interruptions, prolong treatment time, and ultimately affect patient outcomes and quality of life. Currently, there are numerous guidelines on radiation dermatitis, including the Multinational Association of Supportive Care in Cancer (MASCC), British Columbia Cancer Agency (BCCA), Oncology Nursing Society (ONS), and UK Society of Radiographers (SCoR) guidelines. In China, dermatology experts have drafted a consensus. However, due to the differing backgrounds of experts, recommendations among guidelines vary. These guidelines were first developed by Chinese radiation oncologists. The evidence-based guideline in this paper fully considers and adopts China's national conditions; hence, it can be easily applied in daily practice. Radiation-induced dermatitis affects most cancer radiotherapy patients. This research presents China's first guideline by radiation oncologists, addressing prevention and treatment. It emphasizes patient-specific strategies and bridges a crucial gap in the existing literature, catering to the Chinese medical landscape. image