Abstract: OBJECTIVE To explore the changes of cytokines and T lymphocytes in cerebrospinal fluid of children with viral encephalitis（VE） and analyze the clinical significance. METHODS A total of 118 children with VE who were treated in Hainan Women and Children's Medical Center from Jan 2017 to Dec 2020 were assigned as the study group, meanwhile, 40 children of the same age for whom the central nervous system lesions were excluded were chosen as the control group. The levels of cerebrospinal fluid interleukin-2（IL-2）, IL-8, IL-10 and T lymphocyte subsets were compared between the two groups of children, and the values of the cerebrospinal fluid indexes in assessment of illness condition of the VE children were evaluated by receiver operating characteristic（ROC） curve. RESULTS The levels of cerebrospinal fluid IL-2, IL-8, IL-10, CD₈⁺ and CD₁₉⁺ of the study group were significantly higher than those of the control group（P＜0.05）, the levels of CD₃⁺, CD₄⁺ and CD₄⁺/CD₈⁺ of the study group were significantly lower than those of the control group（P＜0.05）. The levels of nerve damage factors neuron specific enolase（NSE） and S100 calcium binding protein B（S100 B） of the severe group were significantly higher than those of the mild group（P＜0.05）. The levels of cerebrospinal fluid CD₃⁺, CD₄⁺ and CD₄⁺/CD₈⁺ of the severe group were significantly lower than those of the mild group, while the levels of IL-2, IL-8, IL-10, CD₈⁺ and CD₁₉⁺ of the severe group were significantly higher than those of the mild group（P＜0.05）. The result of ROC curve analysis showed that the areas under curves（AUCs） of the cerebrospinal fluid IL-2, IL-8, IL-10, CD₃⁺, CD₈⁺, CD₁₉⁺ and CD₄⁺/CD₈⁺ were respectively 0.876, 0.831, 0.859, 0.615, 0.636, 0.872 and 0.731 in assessment of illness condition of the VE children. CONCLUSION The children with VE may have the immune dysfunction, the IL-2, IL-8, IL-10 and CD₈⁺ may be involved in the process of central nervous system damage, and the monitoring of the above indexes may facilitate the clinical assessment of illness condition.