Objective To observe the proportion changes of CD4+CD25+FOXP3+ T cells in peripheral blood of patients with VogtKoyanagiHarada disease (VKH) before and after one month of treatment. Methods he peripheral blood samples from 15 patients with VKH disease before and after one month of treatment by glucocorticoid, and from 15 healthy volunteers were collected，and lymphocytes were separated from them. CD4+CD25+ regulatory T cells were labeled by antibodies of cell surface marker CD4、CD25 and transcription factor FOXP3. The proportion of CD4+CD25+FOXP3+ T cells were detected by flow cytometry. Results Before the treatment, the percentage of CD4+CD25+FOXP3+ T cells in periphery blood was（0.30plusmn;0.19）% of CD4+ cell in VKH patients, and（1.41plusmn;0.52）% in control group, the difference was statistically significant（t=7.665,Plt;0.01）; after one month of treatment, the VKH patients group was（1.28plusmn;0.54）% which close to the control group. However there were two patients whose CD4+CD25+ T cells increased extraordinarily after one month of treatment. Conclusions The proportion of CD4+CD25+ FOCP3+ T cells in periphery blood in VKH patients were lower than control group obviously before treatment, but were close to control group after treatment. Those results indicated that VKH diseases may be associated with the decreased proportion of CD4+CD25+ regulatory T cells.