The enzyme Angiotensin Converting Enzyme-2 is a path how the covid virus enters inside the human cells. Angiotensin Converting Enzyme is a part of renin-angiotensin system. As a result the renin angiotensin system is badly disturbed in Corona Virus Attack. The ACE Inhibitors may possibly be used to decrease the causes of mortality in covid patients. The “3sci” crystal structure of spike protein receptor binding domain from a predicted SARS coronavirus human strain complexed with human receptor ACE2 is chosen as the receptor molecule. It is classified as viral protein and deposited by Wu, Peng and others [ 1 ]. It was predicted that the ACE inhibitors and ARB’s may play an important role [ 2 ] in the clinical trials of covid-19 patients. In this paper, we tried to analyze the role of ACE inhibitor to covid patients. The binding interaction of ACE inhibitors like Benazepril, Captopril and Quinapril with crystal structure of spike protein receptor-binding domain from a predicted SARS coronavirus human strain complexed with human receptor ACE2 were investigated. The various parameters like binding energy, root mean square deviation, inhibition constant, number of hydrogen bonds, amino acids involved in interactions and hydrogen bond interaction of ligands etc. are compared for the molecules to predict the best suitable drug molecule for covid problems.