Abstract: Objective To investigate the diagnostic value of brain natriuretic peptide(BNP) and its amino-terminal precursor(NT-proBNP) in infants with pneumonia complicated with heart failure(HF). Methods Eighty infants admitted to pediatric intensive care unit(PICU) of our hospital due to severe pneumonia from November 2018 to May 2019 were selected as study subjects, who were divided into HF group(40 cases) and Non-HF group(40 cases). The serum levels of BNP and NT-proBNP in the acute phase(within 24 hours after admission) and in the recovery phase of the two groups of infants were measured and compared. Left ventricular ejection fraction(LVEF) was measured in the acute phase of the HF group and its correlation with BNP and NT-proBNP were analyzed. ROC curve was used to compare the diagnostic value of BNP and NT-proBNP for HF. Results The serum levels of BNP and NT-proBNP in the HF group were higher than those in the Non-HF group(all P<0.05), and higher in acute phase than in recovery phase(all P<0.01). Both were negatively correlated with LVEF(r=-0.646, P=0.001; r=-0.592, P=0.001). The area of BNP and NT-proBNP under the ROC curve were 0.665 and 0.683, respectively. Conclusion The serum levels of BNP and NT-proBNP increase when HF is complicated with infant pneumonia, and negatively correlated with LVEF. They have important diagnostic value for early diagnosis of HF, and their diagnostic value for HF is similar.