Pulmonary hypertension(PH) is a heterogeneous group of disorders characterized by increased pulmonary vascular resistance(PVR). The term PH pertains to the hemodynamic profile. PH can be found in different clinical conditions. The non-pulmonary arterial hypertension pulmonary hypertension(non-PAH PH) refers to those forms of PH that are found in group 2 to 5 of the current classification of PH. They included pulmonary hypertension due to left heart disease, pulmonary hypertension due to lung diseases and hypoxemia, chronic thromboembolic pulmonary hypertension, and other diseases. Some advances has been made for the diagnosis and medical therapy of pulmonary arterial hypertension(PAH), but PAH is usually severe and overall quite rare. Non-PAH PH is much more common than PAH, and has been less well studied, especially in terms of diagnosis and medical therapy. The di-agnosis and medical therapy of non-PAH PH would be the hot topics and it is important to conduct further studies.