Abstract: AIM:To investigate the value of plasma apelin-12 (AP-12) and NT-proBNP in diastolic heart failure (DHF) by measuring their levels. METHODS: Seventy-two DHF patients and 30 patients with normal heart function as the control group were included in the study. Levels of plasma AP-12 and NT-proBNP were compared, and their relationship with left ventricular diastolic function was analyzed. RESULTS: The level of plasma NT-proBNP increased significantly in DHF compared with controls, and NT-proBNP showed progressive increases in proportion to cardiac dysfunction degree. Plasma AP-12 levels decreased in DHF compared with those in controls. There was no significant difference among DHF patients with different cardiac diseases. CONCLUSIONS: Plasma AP-12 and NT-proBNP concentrations increased in DHF patients compared with those in controls. Monitoring plasma AP-12 and NT-proBNP levels has some value in diagnosis and assessment of the severity of DHF.