Abstract: Objective: To investigate the clinical value of plasma brain natriuretic peptide(BNP) levels and serum troponin I(cTnI) as biomarkers for the diagnosis of cardiogenic stroke. Methods: The clinical data of 235 patients with acute ischemic stroke(including 66 cases of cardiac stroke and 169 cases of non-cardiogenic stroke).By comparing the plasma BNP and cTnI levels between two groups,the optimal cut-off values of BNP and cTnI levels in the diagnosis of cardiogenic stroke were determined,and the diagnostic value of the two was compared. Results: Compared with the non-cardiogenic stroke group,the older age(P<0.01),larger left atrial diameter(P<0.01),higher incidence of atrial fibrillation and mitral regurgitation(P<0.01),lower incidence of diabetes(P<0.05) and smaller albumin in the cardiogenic stroke group were found(P<0.01).The plasma BNP level and cTnI value in patients with cardiogenic stroke were significantly higher than those in patients without cardiogenic stroke(P<0.01).The area under the ROC curve of plasma BNP level was 0.986,and the 95% confidence interval was 0.972-0.999.The area under the ROC curve of cTnI value was 0.941,and its 95% confidence interval was 0.896-0.987.The optimal cut-off point of plasma BNP level for the diagnosis of cardiogenic stroke was 89.31 pg/mL(sensitivity for 92.4% and specificity for 98.8%),and the optimal cut-off point of cTnI for distinguishing cardiogenic stroke from non-cardiogenic stroke was 0.019 5 ng/mL(sensitivity for 87.9%,specificity for 95.9%). Conclusions: When the plasma BNP level and cTnI value of ischemic stroke patients exceed 89.31 pg/mL and 0.019 5 ng/mL,respectively,it has important clinical significance for the differential diagnosis of cardiogenic stroke and non-cardiogenic stroke,and the clinical value of plasma BNP level in the diagnosis of cardiogenic stroke is higher than that of cTnI.