Abstract: Objective To investigate the effect on reducing pulmanary artey hypertension （PAH） by continuously pumping nitroglycerin （NTG） into the artificial airway.Methods One hundred twenty-seven patients of pulmonary artery hypertension were randomly divided into two groups. In the treatment group, NTG 20 mg was added into 46 mL normal saline （NS） and pumped into the artificial airway for 5-10 mL/h for 1 week. In the control group, phentolamine 10-20 mg was added into 50 mL NS injected intravenously 2-5 μg/（min·kg） for 1 week. BP, CVP, HR, SaO₂, MPAP were monitored. Results At the end of treatment by pumping NTG in artificial airway, pulmonary artery pressure was reduced significantly as compared with phentolamine group（22.7±6.2 vs 36.2±8.3 mmHg） in treatment group（P＜0.05）. Conclusion NTG pumped continuously into artifical airway effectively decreased pulmonary artery hypertension and the effect was prevail over phentolamine I.V.