Cancer-related fatigue (CRF) is the most common and distressing symptom associated with cancer and its treatment. We adopted the Chinese version of the ICD-10 criteria for diagnosis of CRF proposed by Cella et al. to explore the factors causing patients' fatigue. The etiology of CRF is multidimensional and the contributing factors are bio-psychosocial. Symptoms and degree of CRF may differ among various types of tumors. In Chinese society, patients think of CRF as a normal physical and psychological expression. In the evaluation of a cancer patient's symptoms of fatigue, other factors must be included as well. Caregivers must offer cancer patients at different stages of disease early intervention and prevention strategies for CRF, so that the patients' quality of life can be maintained.