Abstract: Abstract: Studies show that the gene evolutionary mechanisms and modes, aminoacylation routes, and evolutionary mechanisms in structure and function of many aminoacyl-tRNA synthetases (aaRS), are diverse in some bacteria and eukaryotes. Thus, further studies on these diversities will be useful in understanding protein structural and functional evolution. Although the essential mechanism responsible for these diversities is not understood, these diversities suggest that certain aspects of the biological processes between bacteria and eukaryotes require further study.