Among some Bacillus species, a protein highly homologous to HU, classified HB and coded by hbs gene. According to the recent studies, the sequence of hbs gene just in one strain of Bacillus subtilis exists in gene bank (ATCC 23857). In this study, DNA from Bacillus subtilis ATCC 6633 was extracted and investigated by PCR. The PCR product was sequenced and shown to differ in just one nucleotide from B. subtilis ATCC 23857. Hence, it was chosen as reference and for the first time, used for non-radioactive labeled probe preparation. The PCR product in Bacillus subtilis with ATCC 6633 was labeled using non-radioactive DIG-labeled nucleotides and conditions of probe preparation and hybridization were optimized and checked it by Southern blotting.