Abstract: OBJECTIVE To preliminary study the effect of bloodstream infection on cardiac load, a retrospective analysis was conducted on the distribution differences of N-terminal brain natriuretic peptide precursor (NT-proBNP) in patients with suspected bloodstream infection (BSI) caused by Gram-positive bacteria, Gram-negative bacteria, or fungi and those whoc had negative result in continuous blood culture. METHODS A total of 174 cases of suspected septicemia or bloodstream infection from Dec. 2012 to Sep. 2016 in the Hainan Branch of PLA General Hospital were selected, and venous blood culture and NT-proBNP test of all the samples were performed on the same day. According to the results of blood culture, the patients were divided into four groups: Gram-positive bacterial infection group, Gram-negative bacterial infection group, fungal infection group and negative control group, and the differences of NT-proBNP in the four groups were compared. RESULTS There was no significant difference in age and gender among the Gram-positive bacterial infection group, Gram-negative bacterial infection group, fungal infection group and negative control group. Comparison of NT-proBNP among the four groups showed that the NT-proBNP level in the Gram-negative bacterial infection group which was 871(301,3688) pg/ml and the NT-proBNP level in the fungal infection group which was 4398(1283, 8436) pg/ml were statistically significantly different from the NT-proBNP level in the negative control group which was 485(146, 1716) pg/ml, and both were higher than that of the control group (P<0.05). There was no significant difference between the other groups. CONCLUSION Increase of NT-proBNP and cardiac load is more likely to occur in patients infected with Gram-negative bacteria and fungi. During the clinical treatment of bloodstream infection, the cardiac load should be monitored in patients with Gram-negative bacterial and fungal infection.