The whole-genome sequencing method allows an analysis of genetic differences between bacterial isolates belonging to the same species. In this study, six strains, including Acinetobacter baumannii ACICU (ST2), A. baumannii ATCC 17978 (ST437), A. baumannii ATCC 19606 (ST57), A. baumannii BJAB0868 (ST2), A. baumannii MDR-TJ (ST2), and A. baumannii SDF (ST17) were investigated. Comparative genome analysis revealed different genomic events on genomes of identical STs. In contrast, the positions of the tRNAs on the genomes showed that the identical STs (ACICU, BJAB0868, and MDR-TJ as ST2) have the exact location map. It appeared that the genomic backbone of identical STs is conserved among them. Still, each strain in the same ST has undergone genomic events on its genomes which can be considered as genome plasticity process.