aroA is an important gene which produces aromatic amino acids essential for bacterial life. The sequence of this gene was shown to be different in bacteria, so the purpose of this study was sequencing of aroA gene in native E. coli O78: K80 to determine the putative differences between this strain and other E. coli O78: K80 strains in gene bank. PCR was used to amplify aroA gene in native E. coli O78: K80. The amplified 1.206 kb PCR product was extracted from Agaros gel, ligated in pTZ57R and sequenced. Blast analysis showed that aroA sequence in native E. coli is different from already submitted homolog gene in Gene Bank. Two amino acids were shown to be different from those already found in other E. coli strains. This different amino acids are Isoleucine and Glycine instead of 39th Threonine and 240th Glutamic acid, respectively. Knowing these differences are important for doing molecular techniques, designing primers and future studies.