Objective To investigate the prediction value of procalcitonin and Cystatin C in the evaluation of patients with sepsis 28 day mortality.Method A total of 106 patients with sepsis in Ezhou central hospital.The expressions of PTC and CysC in the serums of the patients were measured on the first day of the hospitalization by microparticle enzyme immunoassay.Pearson correlation analysis was performed to test the correlation of PTC and Cys-C with PCIS.Logistic regression models were used to examine the risk factors of patients' death.The AUC curve was used to test the value of PTC and Cys-C in prognosis of patients with sepsis.Result After follow-up 28 days:①41.18 ％ patients (n=21) diedat the end of the follow up.②In the death group,the PCT concentration was 67.2 ± 20.6ng/ml,significantly higher than the survival group (44.5± 13 ng/ml,t=-5.57,P＜0.01);the Cys-C was 78.8±21.4 mg/ml,significantly higher than the survival group (64.2±16.9,t=-3.14,P＜0.01).③Pearson correlation analysis showed that the expression of PCT and Cys C in peripheral blood was negatively correlated with PCIS (r =-0.578,-0.761,all P＜ 0.05).④ Multivariate logistic regression showed PTC and Cys-C were the independent risk factors for prognosis of patients with sepsis (P＜0.05).⑤ROC analysis showedthe AUC value of PTC and Cys C were 0.866 (95 ％CI=0.749～0.93),0.87 (95％CI=0.77～0.94)respectly.The AUC value of (PTC & Cys-C) was 0.89 (95 ％CI,0.82～0.95),which wassignificantly increased compared with PTC or Cys-C (both P ＜0.05).Conclusion The combined detection of PCT and Cys-C has good predictive value in the evaluation of mortality in children with sepsis.