Objective: To compare the therapeutic efficacy between intravenous PGE1 and inhaled NO in the treatment of acute pulmonary hypertension. Methods: In 7 dogs, pulmonary hypertension was induced by infusion of the thromboxane analogue U46619 to observe the effect of intravenous administration of small dose PGE1 10 ng/(min*kg), large dose PGE1 50 ng/(min*kg),inhaled NO 4.0×10-5and inhaled NO plus small dose PGE1 on the hemodynamics of acute pulmonary hypertension. We measured the changes of hemodynamic variables after each drug given. Results: Intravenous administration of small dose PGE1 resulted in a decrease in MPAP by (17±8)%, MSAP by (19±10)%, and an increase of CO from (1.21±0.25) L/min to (1.83±0.27) L/min(P＜0.01). Intravenous administration of large dose PGE1 resulted in a decrease in MPAP by (29±7)%, MSAP by (41±11)%, and CO from (1.21±0.25) L/min to (1.04±0.38) L/min (P<0.05). Inhaled NO resulted in a decrease in MPAP by (23±6)%, but no significant changes of MSAP and CO were observed. Inhaled NO plus small dose PGE1 resulted in a decrease in PAPm by (31±7)%, SAPm by (14±9)%, and an increase of CO from (1.34±0.17) L/min to (2.01±0.34) L/min (P<0.01). Conclusion: Inhaled NO plus small dose PGE1 can not only decrease pulmonary artery pressure significantly, but also dilate the system artery and improve cardiac function, which will be useful to blood infusion of other tissues.