Angiotensin Converting Enzyme-2 (ACE2) is a doorway how the virus gets into the body and infect the human to different levels. The spectrum of clinical responses are extremely variable from asymptomatic, sick, really sick, critical to even death. So it is very necessary to workout with the infected protein. We had chosen “3sci” crystal structure of spike protein receptor binding domain from a predicted SARS coronavirus human strain complexed with human receptor ACE2. It is classified as hydrolase/viral protein and deposited by Wu, Peng and others [ 14 ]. It was predicted that the ACE inhibitors and ARB’s may play an important role [ 1 ] 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 various ACE inhibitors like enalapril, lisinopril and ramipril 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.