Abstract: ［Abstract］Objective To study the serum levels of melatonin， tumor necrosis factor alpha（TNF-α）and interferon gamma（IFN-γ）in multiple sclerosis（MS） patients and the correlation with disability. Methods Forty patients with multiple sclerosis were collected as MS group and 30 healthy participants were collected as control group. Serum levels of melatonin and cytokines， including IFN-γ and TNF-， were detected in all participants by the enzyme-linked immunosorbent assay（ELISA）method; disability status of patients with MS was evaluated by EDSS scale. The relevant analysis between serum melatonin， TNF-α， IFN-γ levels and EDSS score in patients with MS was conducted. Results　The concentration of serum melatonin in MS group was significantly lower than control group（P＜0.01）. TNF-α levels were higher than control group（P＜0.05）and the difference was statistically significant between MS patients and control group. Among MS group and control group， no significant correlation with the serum levels of IFN-γ was seen. The serum melatonin level was inversely correlated with EDSS score in MS patients（r = -0.76，P＜0.01），and positively correlated with TNF-α（r = 0.83，P＜0.01） and as compared to IFN-γ，no significant correlation was found （r = 0.17，P＞0.05）. Conclusion The decrease of melatonin and increase of TNF-α can be a factor in the inflammatory reaction in patients with MS，and is closely related with dysfunction occurring in multiple sclerosis. Serum melatonin and TNF-αcan be used as laboratory indicators to monitor clinical curative effect and evaluate prognosis of MS.