Fifty children with refractory idiopathic thrombocytopenic purpura (RITP) were treated with rituximab (n =26) or vincristine (n =24).The response rate,adverse reaction and recurrence rate in two groups were compared.The CD19 +/CD20 + B cells in peripheral blood were detected by flow cytometry in 26 patients before and after RITP treatment.The response rates of rituximab group was significantly higher than that of vincristine group ( 69.2％ vs. 37.5％,x2 =9.74,P ＜ 0.01 ). There was no significant difference in the rate of adverse reaction between two groups ( 11.5％ vs.8.3％,x2 =0.62,P ＞ 0.05 ).The recurrence rate of rituximab group ( 22.2％ ) was significantly lower than that of vincristine group (55.6％,x2 =7.24,P ＜ 0.05 ).In rituximab group the platelet count after treatment was significantly higher than that before treatment ( t =12.48,P ＜0.01 ),and the ratio of CD19 +/CD20 + B cells decreased significantly after treatment compare to that before treatment ( t =6.71,P ＜0.05 ).Rituximab is effective in treatment of refractory idiopathic thrombocytopenic purpura in children,which may be associated with decreased B cells in peripheral bloos.