Cancer anorexia can appear throughout the disease of cancer patients and is often ignored. The disease is common in advanced cancer patients with an incidence of up to 80%. Cancer anorexia is related to the chronic disease or anti-cancer treatment of cancer patients with characters of loss of appetite with or without weight loss negatively affects quality of life and even cancer anorexia-cachexia syndrome which directly affects the survival outcome of patients. Modern medical research believed that cancer anorexia is caused by the failure of normal appetite regulation signal transduction and different from malnutrition or hunger it is caused by metabolic abnormalities. However the current research on the pathogenesis of cancer anorexia has not been completely clear. Most studies believed that pro-inflammatory cytokines such as interleukin-1 tumor necrosis factor-α and interleukin-6 and peripheral hormones such as ghrelin leptin and cholecystokinin central neuropeptide can alter normal regulation signals that govern appetite in different ways and then lead to cancer anorexia. Herein we aimed to review the recent related factors of pathogenesis progress for cancer anorexia and can provide references for further research on evaluation of cancer anorexia and new therapeutic targets.