Objective To establish children's independent normal reference intervals of five coagulation indexes in Chongqing,in order to better provide references for clinic.Methods The plasma samples of 5 119 healthy children were collected and used to detecting prothrombin time (PT),activated partial thromboplastin time (APTT) and fibrinogen (FIB),thrombin time (TT) and D-Dimer (D-D) via Sysmex CS5100 and Sysmex CSA2000.According to ages,the children were divided into 6 groups:newborn (at 0 to less than 15 days of age),newborn (at 15 days to less than 1 month of age),infant (at 1 to less than 7 months of age),children (at 7 months to less than 3 years of age),children (at 3 to less than 7 years of age),children (at 7 to 15 years of age),and comparatively analysed.For normal distribution data,(x)± 1.96s was used to calculate the reference intervals;while for skewness distribution data,the reference intervals was calculated by 95 ％ reference interval according to the percentile of P2.5 and P97.5.Results The normal reference intervals of five coagulation indexes in this clinical laboratory were as follows:PT 11.1-20.2 s (at 0 to less than 15 days of age),10.7-15.8 s (at 15 days to less than 1 month of age),9.9-13.5 s (at 1 month to 15 years of age);APTT 28.8-91.6 s (at 0 to less than 15 days of age),33.3-64.2 s (at 15 days to less tha 1 month of age),24.0-53.2 s (at 1 to less than 7 months of age),21.2-39.2 s (at 7 months to less tha 15 years of age);FIB 1.45-3.52 g/L (at 0 to less than 3 years of age),1.50-3.52 g/L (at 3 to 15 years of age);TT 15.4-26.3 s (at 0 to less than 15 days of age),14.9-21.4 s (at 15 days to less than 7 months of age),14.7-20.1 s (at 7 months to less than 3 years of age),14.9-19.3 s (at 3 to 15 years of age);D-D 0.1-5.1 mg/L (at 0 to less than 15 days of age),0.2-2.2 mg/L (at 15 days to less than 1 month of age),0.1-1.1 mg/L (at 1 to less tha 7 months of age),0.1-1.4 mg/L (at 7 months to less than 3 years of age),0.1-1.3 mg/L (at 3 to less than 7 years of age),0-1.0 mg/L (at 7 to 15 years of age).Conclusion The normal reference intervals of five coagulation indexes,including PT,APTT,FIB,TT and D-D,are established,which provide more accurate references for the diagnosis of related diseases in infants and children in this area.