ACE2 has long been known as an injury protective protein, it can protect a variety of organ damage such as heart, liver, kidney and lung . Especially in cardiovascular diseases, ACE2, as a negative regulator of RAAS, is an extremely important protective factor that mainly plays a role by converting Ang Ⅱ to Ang- (1-7). Nevertheless, with the recent outbreak of COVID-19, it was exposed that another identity of ACE2 is the entry receptor for SARS-CoV-2, which previously served as the entry receptor for SARS . With the in-depth clinical research, it was found that the severity and susceptibility of COVID-19 are related to cardiovascular disease, and SARS-CoV-2 binding to ACE2 receptor is also potentially associated with heart injury symptoms . Therefore, in this article, we mainly review the relationship between ACE2, COVID-19 and cardiovascular system diseases/heart injury.