The Spike protein is one of the virulence factors of viruses, which is responsible for the attachment of the virus to the host cell. This study included the study of the effect of Favipiravir on S protein at different concentrations, as it showed the highest effect at a concentration of 0.5 and an amount of 9.66 ± followed by the concentration. .025 by 7.06 ± to have a gradual effect of (5.23 ± ,, 3.63 ± 2.53 ±, 1.60 ±, 0.06 ±, 0.00) at a concentration of (0.015, 0.03, 0.06, 0.125, 0.07, 0.02), respectively, as once the virus interacts with the cell The host causes a structural rearrangement of the S protein, which allows the virus to fuse with the host cell membrane. Because of the seriousness of the Covid-19 virus and its components, it has become necessary to find a drug that controls the spread of the pandemic.