Objective The management of fluid infusion is crucial in severe sepsis/septic shock patients.The correlation of extravascular lung water index(EVLWI) versus oxygenation index ( PaO2/FiO2 ) and EVLWI versus intrathoracic blood volume index(ITBVI) were analysed in this present study. Method Totally 24 patients,admitted to the Intensive Care Unit of Second Affiliated Hospital of Zhejiang University, College of Medicine and diagnosed as severe sepsis/septic shock with acute lung injury and/or acute respiratory distress syndrome,were enrolled. ITBVI and EVLWI were detected with PiCCO technique. Correlation of EVLWI and PaO2/FiO2, ITBVI and EVLWI were analysed,respectively. Simple correlation and simple linear regression were used for statistical analysis. Results Significant negative correlation was found of EVLWI and PaO2/FiO2 ( r = - 0. 45, P ＜ 0.01).EVLWT = 14 mL/kg was defined as the cutoff value for the subgroup analysis. No correlation was found between EVLWI and PaO2/FiO2 in the subgroup with EVLWI≤ 14 mL/kg ( r = 0. 12, P = 0.243), but in the subgroup with EVLWI ＞ 14 mL/kg, significant negative correlation was found ( r = - 0. 47, P ＜ 0. 01 ). When EVLWI was higher than 14 mL/kg,EVLW should be decreased to improve oxygenation and other aspects should be taken into account. No significant correlation was found between ITBVI and EVLWI. A ITBVI value 1000 mL/m2 was also defined as the cutoff value for the subgroup analysis. No significant correlation was found in the subgroup with ITBVI≤ 1000 mL/m2( r = 0.13, P = 0.17), while significant positive correlation was found in the subgroup with ITBVI ＞ 1000 mL/m2. This result suggested that in patients of severe sepsis/septic shock with ALI/ARDS, when the blood volume is high, ITBV should be decreased to improve the oxygenation,however,it is not useful in the situation of high pulmonary vascular permeability. Conclusions Extravascular lung water has a important role in the fluid management in patients of severe sepsis/septic shock with ALI/ARDS.