A cluster of pneumonia (COVID-19) cases have been found in Wuhan China in late December, 2019, and subsequently, a novel coronavirus with a positive stranded RNA was identified to be the aetiological virus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2), which has a phylogenetic similarity to severe acute respiratory syndrome coronavirus (SARS-CoV). SARS-CoV-2 transmits mainly through droplets and close contact and the elder or people with chronic diseases are high-risk population. People affected by SARS-CoV-2 can be asymptomatic, which brings about more difficulties to control the transmission. COVID-19 has become pandemic rapidly after onset, and so far the infected people have been above 2 000 000 and more than 130 000 died worldwide according to COVID-19 situation dashboard of World Health Organization (https://covid19.who.int). Here, we summarized the current known knowledge regarding epidemiological, pathogenesis, pathology, clinical features, comorbidities and treatment of COVID-19/ SARS-CoV-2 as reference for the prevention and control COVID-19.