The COVID-19 pandemic has caused severe health problems: acute respiratory distress syndrome and progressive alteration of some inflammatory and coagulative parameters. Heparin and low molecular weight heparin are the mostly used anticoagulant for the prevention and treatment of thrombosis, therefore have been recommended by WHO to apply to moderate-severe COVID-19 patients. He-parin and low molecular weight heparin possesses other biological activities inclu-ding anticoagulant, anti-inflammatory and direct antiviral activities, increasing the release of hepatic lipase and lipoprotein lipase, suppressing complement activa-tion, inhibiting angiogenesis, and modulating tumor progress and metastasis.