Objective To analyze the correlationship of electrocardiogram QRS complex and plasma level of brain natriuretic peptide (BNP) with clinical heart function,and to discuss their roles in predicting the prognosis in patients with heart failure. Methods Two hundred and eighty-two patients with confirmed diagnosis of heart failure were enrolled. NYHA class was evaluated. QRS complex duration and plasma level of BNP were measured. The mortality and readmission were analyzed after the patients were followed up for 6 months. Results The plasma level of BNP increased and QRS complex duration prolonged when patients moved from NYHA classⅠto classⅣ. The increased BNP level was associated with wider QRS complex,lower left ventricular ejection fraction and deteriorated heart function. Multivariate analysis showed that the prolonged QRS duration and elevated BNP level were the two independent risk factors of death or readmission. Conclusion The prolongation of QRS duration and the elevated BNP level are predictive of a poor clinical heart function and poor prognosis in patients with heart failure.