Cancer patients are prone to decreased intake and tumor-specific metabolic abnormalities due to factors such as the tumor itself and the treatment received and the need for nutrients varies from that of the non-cancer population. The nutritional needs of such special status population need to be met by food for special medical purposes FSMP but there is no guideline for FSMP for cancer patients. Due to the lack of understanding of the particularity of nutritional needs of cancer patients the mechanism of metabolic disorders and the efficacy of nutritional therapy it leads to the limitations and irregularities of the application of FSMP in clinical practice. In order to standardize the application of FSMP and guide the practice of clinical nutrition therapy experts from Key Laboratory of Cancer FSMP for State Market Regulation Formula Food for Special Medical Purposes Application Committee China Nutrition and Health Food Association and Chinese Society of Nutritional Oncology collected analyzed discussed and summarized important relevant clinical study evidence and authoritative guidelines published in recent years under the guidance of evidence-based medicine and developed this FSMP guideline for cancer patients for the reference of clinicians dietitians clinical pharmacists hospital managers and patients and caregivers.