Background : Pulmonary arterial systolic and diastolic pressure can be estimated from peak tricuspid regurgitation(TR) velocity and end-diastolic pulmonary regurgitation(PR) velocity. Although the clinical significance of systemic arterial pulse pressure is well known, the clinical implications of pulmonary arterial pulse pressure(PPP) has not been investigated. We investigated the relationship of PPP with age, left ventricular dimension, systolic and diastolic functions and other clinical factors. Methods and results : Fifty four patients without serious cardiopulmonary disease were enrolled.(Mean age; 64.2짹12.2 years, M:F=22:32) The prevalence of hypertension and diabetes were 51.9% and 7%. Mean left ventricular(LV) end-diastolic/systolic dimension, left atrial size and ejection fraction(LVEF) were 45.3짹6.3/29.3짹7.5mm, 38.2짹4.64mm and 57짹6.4%, respectively. The end-diastolic transpulmonic pressure gradient(EDPG) and peak systolic trantricuspid pressure gradient(PGTR) were recorded by Doppler echocardiography. (Mean PPP, PGTR and EDPG were 22.7짹7.3, 26.3짹8.1 and 3.5짹2.0 mmHg) When patients with abnormally low(n=13) and high PPP(n=17) were compared, the patients with low PPP were older(70.5짹9.2 vs 60.3짹14.4 years, p=0.035), had lower E���, longer deceleration time of mitral inflow.(4.3짹1.3 vs 6.3짹2.8mmHg, p=0.016; 229짹42.3 vs 203짹35.4 msec, p=0.081), and higher estimated pulmonary artery diastolic pressure(EDPG; 5.8짹2.1 vs 2.0짹1.2mmHg p<0.001) although estimated pulmonary systolic pressure were not different (PGTR; 27.2짹7.6 vs 27.7짹8.4mmHg, p=0.891). EDPG showed a negative correlation with E and E��� velocity(r=-0.315, p=0.027; r=-0.253, p=0.080). Conclusion : Contrary to systemic artery pulse pressure, pulmonary artery pulse pressure showed reverse correlation with age. PPP was negatively correlated with the parameters of LV diastolic function by increasing pulmonary artery diastolic pressure.