Abstract: AIM:To evaluate the effect of ambrisentan on pulmonary hypertension after the surgery of congenital heart disease. METHODS: Seventy patients with pulmonary hypertension after surgery for congenital heart disease from February to December 2013 were selected. Patients were randomly divided into experimental group (n=35) and control group (n=35). The experimental group received the combined treatment of ambrisentan and conventional therapy, whereas the control group received conventional therapy only. Outpatient follow-up was conducted in all patients after 12 weeks and cardiac function was assessed by evaluation of pulmonary artery pressure using cardiac ultrasound. Liver and kidney function were also measured. RESULTS: Pulmonary artery pressure in both experimental groups ［(38±5) vs.(50±6) mmHg, P<0.05］ and control group (41±6) vs.(47±7) mmHg, P<0.05］ after 12 weeks significantly decreased compared with the values 3 days after surgery. However, decrease of pulmonary artery pressure in the experimental group was remarkably greater than in the control group ［(12±4) vs.(6±3) mmHg, P<0.05］. More improved cardiac functions were observed in 30 patients in the experimental group (86%) than in 25 patients in the control group (71%). No cases of liver damage and anemia were observed in both groups. CONCLUSION: Application of ambrisentan in patients with pulmonary hypertension after surgery for congenital heart disease is safe and effective in reducing pulmonary artery pressure and improving cardiac functions.