The 2019 novel coronavirus (2019-nCoV) was discovered in an unidentified viral pneumonia case in Wuhan, China in December 2019, and was named by the World Health Organization (WHO) on January 2,0. The disease caused by 2019-nCoV was named corona virus disease 2019 by WHO on February 2,0. Recent studies have shown that angiotensin converting enzyme 2 (ACE2) is likely to be a mediating receptor of 2019-nCoV-infected cells, and ACE2 is mostly expressed in type Ⅱ alveolar cells in the human lung cells. The high expression of ACE2 in type Ⅱ alveolar cells may explain acute respiratory distress syndrome (ARDS) after 2019-nCoV infection. The first completed pathologic dissection of a patient who died of 2019-nCoV-pneumonia revealed diffuse alveolar injury and lung transparent membrane formation, consistent with ARDS.