Deoxyribonucleases (DNases) are the enzymes which can break phosphodiester bonds of DNA. Nucleases are key components of biological processes such as DNA replication, repair and recombination, antiviral defense and apoptosis. The most well characterized deoxyribonucleases are DNase I and DNase II. DNase I have endonucleolytic properties yielding primarily 5’-phosphodi- and oligonucleotide end products and they are more widespread than DNase II. Many pathogenic bacteria produce DNase and in this study diversity of the deoxyribonuclease I among 13 genera of Enterobacteriaceae was examined. Thirty-nine protein sequences of the DNase I were extracted from NCBI and then multiple alignment and phylogenetic tree were performed using MEGA 6 software. The results show that in spite of difference between the sequences because of deletion, insertion and amino acid substitution, there are some conserved parts in them which can be used for designing universal primers for gene amplification.