Abstract: OBJECTIVE To investigate and analyze the dynamic characteristics of blood lactic acid（Lac）,troponin and coagulation indexes in children with severe sepsis and the relationship with prognosis. METHODS Total of 72 children with severe sepsis from Oct. 2015 to May 2018 were recruited as the observation group; 65 children with no obvious symptoms of infection in the intensive care unit during the same period were chosen as the control group. Then the blood lactic acid,troponin and coagulation indexes in the observation group and control group at admission,24 h and 72 h after admission were detected and compared, and the indexes between the observation group with survival and death were compared too. The relationship between these indexes and the prognosis of the disease in children were analyzed by Pearson correlation. RESULTS The blood lactic acid,troponin and coagulation indexes in the observation group at admission, 24 h and 72 h after admission were all significantly higher than that in the control group; the levels in the observation group continuously increased（P＜0.05）. The detection results in the observation group with death were significantly higher than that in the observation group with survival（P＜0.05）. the Pearson correlation showed that the blood lactic acid,troponin and coagulation indexes at admission were all positively correlated with prognosis（P＜0.05）. CONCLUSION The blood lactic acid,troponin and coagulation indexes in children with severe sepsis were obviously abnormal, which may have active response value for the prognosis of the disease.