Coronavirus is a non-segmented virus related to Coronaviridae family with an envelope and RNA that has a huge positive-sense single-stranded genome. The causative agent of COVID-19, severe acute respiratory coronavirus syndrome-2 (SARS-CoV-2) first appeared in China in 2019. The role of these viruses in pneumonia has greatly improved through molecular techniques. The virus structural proteins, viral replication factors, viral endocytosis process and enzymes are the key targets for designing drugs against COVID-19. This review considered the main molecular and cellular targets as well as peptide-based and pharmaceutical treatments for COVID-19 aiming for a better design of drugs against viruses with the best insights on key factors in this infection.