Cancer-related fatigue survivors have been found to have lower morning serum cortisol levels, flattened diurnal cortisol cy-cles, and decreased cortisol responses to psychological stress. The mechanism may be related to the inflammation caused by disorder of hy-pothalamus-pituitary-adrenal axis, and there are also some evidences to support that cortisol can be used to reduce cancer-related fatigue. This study introduced the research progress of the relationship between cancer-related fatigue and hypothalamus-pituitary-adrenal axis.