Left heart disease associated pulmonary hypertension is the most common type of pulmonary hypertension, classified as type 2 pulmonary hypertension. Accurate diagnosis of pulmonary hypertension is of great significance in the diagnosis, treatment and prognosis of left heart disease. Right heart catheterization is the gold standard for the diagnosis of pulmonary hypertension. In recent years, right heart catheterization has been applied to the study of left heart disease associated pulmonary hypertension. In this paper, we reviewed the application of right heart catheterization in left heart disease associated pulmonary hypertension.