Abstract: Objective To explore the clinical application value of plasma N-terminal pro-B-type natriuretic peptide (NTproBNP) in diagnosis and treatment of symptomatic patent ductus arteriosus (sPDA) in preterm infants. Methods A total of 107 preterm infants with gestational age of 28-32 weeks and birth weight less than 1500 g who were admitted to the neonatal intensive care unit from October 2013 to September 2014 were recruited. Plasma NT-proBNP were on 4th and 7th day after birth. The echocardiography examination was performed within 30 minutes after the blood was drawn. According to the echocardiography examination on 4th day after birth, the infants were divided into the patent ductus arteriosus (PDA) group (n = 39) and the control group (n = 68). According to whether there were significant hemodynamics changes of ultrasonography and clinical symptoms, the PDA group were classified into the sPDA group (n = 20) and the asymptomatic PDA group (asPDA, n = 19). Then according to whether ibuprofen was taken, the sPDA group was further divided into treatment group (n = 13) and non-treatment group (n = 7). Results On the 4th day after birth, the level of plasma NT-proBNP in the sPDA group was significantly higher than that in asPDA group, and the level of plasma NT-proBNP in asPDA group was significantly higher than that in the control group (P < 0.05). On the 7th day after birth, the level of plasma NT-proBNP in the sPDA group was significantly higher than that in the asPDA group and the control group (P < 0.05), and, however, there was no significant difference between the asPDA group and the control group (P > 0.05). In the treatment group, the level of plasma NT-proBNP on the 7th day after birth was significantly lower than that on the 4th day after birth (P < 0.05). In the non-treatment group, there was no significant difference of the plasma NT-proBNP between the 4th day and the 7th day after birth (P > 0.05). In PDA group, the level of plasma NT-proBNP on the 4th day after birth was positively correlated with ductus arteriosus (DA) diameter, ratio of the left atrium to aortic root diameter (LA/AO ratio) and transductal diameter-to-left pulmonary artery ratio (TDD/LPA) (r = 0.498-0.670, respectively). The area under receiver operator characteristic (ROC) curve for prediction of sPDA by the plasma NT proBNP on the 4th day after birth was 0.969 (95% CI: 0.938-1.000). When the NT-proBNP was 13964 pg/ml on the 4th day after birth, the sensitivity for diagnosis sPDA was 95%, the specificity was 95.4%. Conclusions The level of plasma NT-proBNP is significantly higher in preterm infants with sPDA and is decreased after treatment. Plasma NT-proBNP on the 4th day after birth is a sensitive marker for predicting sPDA. Dynamic monitoring of plasma NT-proBNP has important clinical value in selection of the treatment strategy in preterm infants with PDA.