Objective To investigate the correlation between myocardial fibrosis evaluated by cardiac magnetic resonance (CMR)T1 mapping and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in elderly patients with ischemic cardiomyopathy (ICM).Methods The 56 hospitalized patients with ICM(ICM group)and 20 healthy volunteers(control group)were recruited in cardiology department of Henan Provincial People's Hospital from April 2014 to June 2017.Clinical data,serum NT-proBNP detection,CMR T1 mapping and contrast-enhanced scan were determined,retrospectively collected and compared between two groups.The differences in myocardial extracellular volume fraction(ECVF)and NT-proBNP levels were compared among the control group,the ICM group and the ICM subgroups with different degree of cardiac dysfunction.The correlation between ECVF and NT-proBNP level was analyzed.Results The levels of ECVF and NT-proBNP were significantly higher in ICM group than in control group[(35.1t6.2)％ vs.(25.3±2.2)％ for ECVF,and(3 902.7± 1 670.3)ng/L vs.(280.5± 140.5)ng/L for NT-proBNP,t =6.917 and 9.645 respectively,both P＜0.01].Along with NYHA Functional Class upgrade of Ⅱ to Ⅲ] to Ⅳ of the ICM subgroups,the levels of ECVF and NT-proBNP were significantly increased (F =18.372 for ECVF,61.82 for NT-proBNP,all P＜0.01).There was a positive correlation between ECVF and NT-proBNP level in ICM patients (r =0.666,P ＜ 0.05).Conclusions Serum NT-proBNP level is correlated with the degree of myocardial fibrosis,which might be used as an indicator of myocardial fibrosis in ICM patients.