Objective：To analyze risk factors of chronic childhood immune thrombocytopenia（ITP），and to provide basis for early judging the prognosis and treatment of ITP. Methods：A total of 161 inpatients diagnosed with ITP in the Pediatrics Department of the Affiliated Huai’an No.1 People’s Hospital of Nanjing Medical University between January 2019 and December 2021 were selected as the research subjects，and they were followed up for more than one year. According to the course of the disease，they were divided into non-chronic ITP group（84 cases）and chronic ITP group（77 cases）. Multivariate logistic regression analysis was conducted to analyze the independent risk factors of chronic ITP. The efficacy of the model was evaluated by receiver operating characteristic（ROC）curve， calibration curve and decision curve analysis（DCA）. Results：①Independent risk factors for chronic ITP included age，helper T cell （Th）/killer T cell（Tc），serum cystatin C and serum C3（P＜0.05）. ②The areas under the ROC curves to predict chronic ITP by age， Th/Tc，serum cystatin C and serum C3 and their combination were 0.725（95％CI：0.647~0.804），0.741（95％CI：0.665~0.817），0.706 （95％CI：0.626~0.785），0.635（95％CI：0.550~0.720），0.853（95％CI：0.794~0.911），respectively. ③The calibration curve is close to the ideal curve. ④The DCA curves showed a better performance of the prediction model in the 0.10~0.85 threshold probability range. Conclusion：Age，Th/Tc，serum cystatin C and serum C3 are independent influencing factors in children with chronic ITP，and their combination shows a better predictive value for the prognosis.