Abstract: ObjectiveTo explore the predictive value of clearance of blood lactate and serum procalcitonin for prognosis at 28 d of septic shock in children. MethodsA retrospective analysis was done in 50 cases of children with septic shock from February 1st 2017 to February 1st 2019. They were divided into survival group and dead group. The predictive value of Sequential Organ Failure (SOFA) Score, clearance of blood lactate and clerance of serum procalcitonin for prognosis at 28 d of septic shock in children was evaluated by receiver operator characteristic curve. ResultsFifty cases of children with septic shock were analyzed, including survival group (n=33) and dead group (n=17). ①Compared with the survival group, SOFA Score, CPR and N-terminal pro-B-type natriuretic peptide were higher (P＜0.001, =0.041，=0.017,respectively), and platelet count was lower（P=0.010）in dead group. The cases of celiac infection in survival group was higher than that in dead group (P=0.040). ② Blood lactate level at initial stage and after 6 h, serum procalcitonin level at 120 h in dead group were higher than those in survival group (P =0.043, <0.01, =0.044, respectively). Lactate clearance rate and the PCT clearance rate on 24 h,48 h,72 h and 120 h were obviously lower in the dead group(P<0.00,<0.001,=0.009,=0.033,=0.006, respectively). ③The predictive value for prognosis in children with septic shock: Yoden index of serum PCT clearance rate at 120 h was the highest（F=3.631，P =0.015）. The area under the AUC curve of combined index (SOFA score>11.5, lactate clearance rate on 6 h<15.8% and the PCT clearance rate on 120 h<70.8%) was 0.986, Yoden index was 0.892, the sensitivity was 96.9%, the specificity was 92.3%. ConclusionThe SOFA score, serum lactic acid clearance rate at 6 h and serum PCT clearance rate at 120 h had a good evaluation value for the prognosis of children with septic shock. The combined application of the three indexes can improve the forecasting efficiency.