The APJ is a class A, rhodopsin-like G protein-coupled receptor (GPCR) with high sequence similarity to the angiotensin receptor AT1. APJ has been shown to be widely expressed in humans tissues, including the central nervous system, cardiovascular system, adipocytes and others. APJ plays an important role in the occurrence and development of cardiovascular and metabolic diseases including atherosclerosis (AS), coronary heart disease (CAD), heart failure(HF), pulmonary arterial hypertension (PAH), myocardial hypertrophy and atrial fibrillation, especially hypertension. Previous researchers found that apelin/APJ could induce vasodilation and then reduce blood pressure. Despite APJ is closely associated with many diseases, there are no drugs that can activate or inhibit APJ directly. In the current review, we have summarized recently reported peptides, small molecule agonists and antagonists targeting APJ. Given the role of apelin/APJ in hypertension and other cardiovascular diseases, we believe that the peptides and compounds based on APJ will be developed for treatment of these diseases.