The aim of this study was to investigate the expression and immunologic regulation function of interleukin-23 and its related cytokines in chronic idiopathic thrombocytopenic purpura (ITP) patients. Levels of cytokines in peripheral blood mononuclear cells (PBMNC) were detected by reverse-transcription real-time polymerase chain reaction in 30 patients with chronic ITP and 15 healthy volunteers. The quantity of IL-23, IL-12, IL-17 in serum was detected by enzyme-linked immunosorbent assay (ELISA). The results showed that low detectable mRNA levels of IL-23p19, IL-12p35, IL-27 and IL-12p40 were found in all patients and healthy persons. Trace of IL-17 mRNA were expressed in PBMNC of part of patients and normal controls. Levels of IL-12p35, IL-27, IL-17 mRNA between healthy persons and chronic ITP patients were not statistically different. Compared with normal controls, patients showed the lower expression levels of IL-23p19 and IL-12p40 mRNA (p < 0.01). The IL-12 levels of chronic ITP patients were significantly higher than that of normal controls (p < 0.01). The IL-23 and IL-17 levels of chronic ITP patients were same to that of normal controls. It is concluded that the imbalance of T cell subsets in ITP patients mainly associated with IL-12, but not with IL-23 and IL-17.