A novel and related to severe acute respiratory syndrome associated coronavirus (SARS-CoV2) has been identified as an infectious coronavirus originating from a Wuhan seafood market and rapidly spreading into and beyond China. While non-conserved regions of viral genome can lead to novel coronavirus subtypes, conserved regions are also very important for drug and vaccine researches. In our study, together with SARS-CoV showing high sequence similarity with SARS-Cov2, also genome and protein sequence alignments of non-lethal OC43 and HCoV-HKU1 viruses for SARS-CoV2 were performed in the regions shown as drug targets. The genomic sequence similarities of SARS-CoV2 with SARS-CoV are 79% between 6-1923 bp, 82% between 3956-21577 bp, 80% between 22539-27910 bp and 90% between 28257-29894 bp, respectively. Major similar region of OC43 spike protein with SARS-Cov2 is located in the C terrminus, 2 other conserved regions with lower similarity were detected in N- terminus of S protein. HCoV-HKU1, has a 73% similarity between 14348-15992 bp in the genomic sequence of SARS-CoV2 RNA-dependent RNA polymerase (RdRp). Similar regions of relatively harmless HCoV-HKU1 with SARS-CoV2 for RdRp can contribute understanding active sites of RdRp and developing a specific drug target. Antiviral approaches to the conserved regions of the RdRp protein have the potential to protect against existing and possible novel coronavirus species. Although lethal coronaviruses contain a large number of non-conserved regions compared to relatively harmless respiratory pathogens, existance of the conserved regions for replication and understanding functional importance of these regions may be vital to develop effective treatment methods.