Pulmonary arterial hypertension (PAH)is a complication of congenital heart disease (CHD). In clinic, Right heart catheterization (RHC)can obtain the pressure of pulmonary arteries and transthoracic echocardiography (TTE)can acquire the velocity of pulmonary blood flow. However, neither RHC nor TTE can provide quantitative hemodynamics. Here, we use computational fluid dynamics (CFD)to study the hemodynamics of pulmonary arterial of patients with PAH associated with CHD. Compared with the normal pulmonary blood flow, the local hemodynamics, especially wall shear stress (WSS), energy loss (EL)and streamlines, displayed obvious differences in the patients with PAH-CHD. Lower WSS, higher EL and rotating flow were generated in the pulmonary artery with PAH-CHD. These results may have a close association with endothelial dysfunction and accelerate the progression of PH.