Abstract: Objective To investigate the effects of the roxithromycin on cancer cachexia and to study the related mechanism using mice with cancer cachetic as animal model. MethodsMale BALB/c mice bearing colon 26 adenocarcinoma for 9 days were served as models of cancer cachexia. The mice were divided into three groups: healthy control group, cancer cachexia with saline group, and cancer cachexia with roxithromycin (RM) group. Physiological conditions, bodyweight and food intake were documented every day. Serum levels of cytokine and nutritional markers were detected seven days after treatment. Results Tumor-bearing caused a decrease of body weight and metabolic disturbance after the removal of tumor. Serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels were significantly elevated accompanied with nutrition depletion in tumor-bearing mice.In the RM-treated group,the gastrocnemius muscle weight was increased, the concentration of serum glucose was increased,and the serum TNF-α and triglyce ride were decreased. Conclusion RM may have the potentials to moderate cancer cachexia state and adjust metabolic disorder through down-regulating the serum level of TNF-α.