Objective:To investigate the changes of inflammatory cytokines interleukin-8 (IL-8),tumor necrosis factor alpha(TNF-α)and high-sensitivity C-reactive protein(hs-CRP) in children in different phases of mycoplasma pneumoniae pneumonia(MPP). Methods:Sixty children with MPP and thirty healthy children were recruited from January 2009 to December 2011 in Nanjing Hospital Affiliated to NJMU. The mass concentration of the IL-8 and TNF-α was measured by enzyme linked immunosorbent assay(ELISA),the concentration of hs-CRP was measured by immune turbidimetry. The serum levels of the IL-8,TNF-α and hs-CRP were compared in different phases and stages with one-way analysis of variance(one-way ANOVA). Results:The serum levels of the IL-8 and TNF-α in the children with MPP in both acute stage and convalescence stage were significantly higher than normal control(P < 0.01). The levels of IL-8 and TNF-α in the severe cases were higher than those in the mild cases(P < 0.01). The level of the hs-CRP in the severe cases was higher than those in the mild cases and normal control in acute stage(P < 0.01). While there was no significant difference in the level of hs-CRP among three groups in convalescence stage (P > 0.05). Conclusion:Inflammatory cytokines of IL-8,TNF-α and hs-CRP play important roles in the pathogenesis of MPP. They can be used as monitoring indicators to reflect the severity of pneumonia.