Purpose: An elevated brain natriuretic peptides (BNP) level is a significant predictor of in-hospital mortality in acute decompensated heart failure with either reduced or preserved systolic function. The ratio (E/E) of early diastolic mitral inflow velocity (E) over early diastolic mitral annulus velocity (E) has been suggested as an index representing left ventricular (LV) filling pressure. The aim of this study was to evaluate the factor affecting the pro-BNP in patients presenting acute pulmonary edema and preserved systolic function. Methods: We enrolled consecutively 104 patients (71.4짹11.4yrs) with acute pulmonary edema and preserved systolic function from may 2006 to may 2007. The preserved systolic function was defined as LV ejection fraction ��� 45%. We measured the laboratory parameters including cell blood count, creatinine, C-reactive protein (CRP), pro-BNP at admission and echocardiographic parameters like LV mass index (LVMI) and mitral inflow and annulus velocity. Results: In univariate analysis, the level of pro-BNP was positively correlated to hemoglobin(r=-0.297, p=0.003), creatinin (r=0.315, p=0.002) and E/E���(r=0.336, p=0.004). In multivariate analysis, after adjusting age, the history of hypertension, diabetes and smoking, hemoglobin, LVMI, the creatinin and E/E���were independent predictor for elevated pro-BNP. Conclusions: The E/E���might be independent predictor for elevated pro-BNP in patients with acute pulmonary edema and preserved systolic function. However, further larger study might be needed