Abstract: Objective To probe into the neuro-immune mechanism of chronic fatigue syndrome and the intervention effects of physical exercise.Methods Forty male SD rats were randomly divided into 4 groups: control group, model group, exercise model group and exercise group.The rat model of chronic fatigue syndrome was made by sleep deprivation and overload exhaustive swinming Exercise model was made with 8-week spontaneous wheel running.The concentration of 5-hydroxytryptam ine (5-T) in hippocam pus and occipital cortex was measured with high perfoun ance liquid chrom atography.ELISA was employed to measure levels of in terferon-γ-(IFN-γ)and interleukine-4(IL-4)in serum,and the ratio of IFN-γ/IL 24.Results Compared with the control group,the concentration of 5-HT,the level of IFN-γ and the ratio of IFN-γ/IL-4 were significantly decreased in model group(P<0.01).Compared with the model group,rats in exercise model group had higher levels of 5-HT,IFN-γ and a higher ratio of IFN-γ/IL-4(P<0.05).The concertration of 5-HT was significantly increased in the exercise group than that of in the control group(P<0.05).Conclusion As an effective p rotection measure,long-term exercise can lower neuroimm unity injury caused by chronic fatigue syndrome.