Objective: To investigate the effects of fibrin degradation products (FDP)

monocyte/lymphocyte ratio (MLR) and neutrophil/lymphocyte ratio (NLR) in peripheral blood on survival and prognosis in children with severe pneumonia. Methods: A total of 310 children with pneumonia admitted into The People’s Hospital of Dazu from Jan. 2015 to Jan. 2018 were extracted to be divided into 162 children with severe pneumonia (severe pneumonia group) and 148 children with common pneumonia (common pneumonia group) according to the severity of the disease. And 58 healthy children were extracted as the control group. Levels of FDP

NLR and MLR in peripheral blood were detected and compared

and the predictive value of FDP

MLR and NLR in peripheral blood on the survival prognosis of children with severe pneumonia was analyzed. Results: The levels of FDP

NLR and MLR in severe pneumonia group were respectively higher than those in the common pneumonia group and the control group

and the levels of FDP

NLR and MLR in the common pneumonia group were higher than those in the control group (P<0.05). The levels of FDP

MLR and NLR in peripheral blood in the severe pneumonia death group were higher than those in the survival group

with statistically significant difference (P<0.05). Multivariate Logistic analysis showed that elevated levels of FDP

MLR

and NLR in peripheral blood were independent risk factors affecting the survival and prognosis of children with severe pneumonia. The results of ROC curve showed that the area under the curve for predicting the survival and prognosis of children with severe pneumonia by combined detection of FDP

MLR

and NLR in peripheral blood was 0.891

and the sensitivity and specificity were 0.914 and 0.813

respectively. Conclusion: Changes of FDP

MLR

and NLR in peripheral blood are independent risk factors that affect the prognosis of children with severe pneumonia. Elevated FDP

MLR and NLR have significant predictive value for the survival and prognosis of children with severe pneumonia.