Abstract
The SARS-CoV-2 has infected over 194,909,000 cases and over 4,170,000 deaths in the world before the end of July 2021. The virus attacks human alveoli and induces severe lung injury (COVID-19 disease) and spreads rapidly. The mechanisms of COVID-19 disease are unclear. To better understand this disease, This review analyzes the SARS-CoV-2 biological characteristics, insights the effect of alveolar epithelium and its adjacent microvascular endothelium, investigates human host cells immune response and immunothrombosis. Explains clinical manifestations of COVID-19 associated lung injury. It may be helpful for development management strategies for COVID-19 associated pulmonary damage.