The SARS-CoV-2 pandemic is an urgent global public health emergency and warrants investigating studies on bonafide antivirals for combat. Here we report the drug target and mechanism of action of potential antiviral drug Arbidol for SARS-CoV-2 infections. Our structural and molecular dynamics studies show how Arbidol targets the SARS-CoV-2 spike glycoprotein and impede the trimerization of spike glycoprotein, which is a key for host cell adhesion and hijacking, thus placing Arbidol as a potential drug for repurposing. This study also abets in the development of other new therapeutics for COIVD-19 disease based on Arbidol binding mode and using structure-guided drug designing. Copyright © 2020. Published by Elsevier B.V.