Sarcopenia is a progressive generalized syndrome characterized by decreased skeletal muscle content and decreased function which is common in the elderly. It not only causes dysfunction but also increases the risk of fractures falls complications and even death. However more and more studies have found that sarcopenia is more common in patients with tumors and that sarcopenia associated with malignant tumors is called tumor - associated sarcopenia. In a variety of tumors such as gastrointestinal tumors head and neck tumors breast cancer and lung cancer the high incidence of tumor-related sarcopenia is not only related to the toxic side effects of chemotherapy and radiotherapy and postoperative complications but also seriously affects the long-term survival of patients. At present the research on tumor - related sarcopenia is in the exploratory stage and multi - center large - sample prospective evidence-based research is still needed to further reduce the occurrence of related adverse reactions and improve the quality of life of patients. This article reviews the definition evaluation and diagnostic criteria of tumor-associated sarcopenia as well as the correlation between tumor-related sarcopenia and the treatment of toxic side effects postoperative complications and survival prognosis in tumor patients in different tumors aiming to clarify the important clinical value of sarcopenia in the prognosis of tumor patients and provide a basis for further large-scale clinical research.