Urinary tract infections (UTI) due to Proteus mirabilis strains represented nearly 90% of Urinary tract infection cases. In this study the effect of applying extremely low frequency   square magnetic pulses ELF-SMP on P. mirabilis was investigated. While, it interferes with the bioelectric signals generated during the cell division process. Also, the effect of exposure on bacterial antibiotic susceptibility and morphological cellular structure was studied. The results indicated that there was a significant inhibition effect for P. mirabilis exposed to 0.6 Hz SMP for one hour and significant increase in antibiotic susceptibility to DNA, proteins, β-lactamase enzyme and cell-wall synthesis inhibitors. Additionally, results of dielectric relaxation and TEM indicated  molecular and morphological changes. According to these aforementioned results, it was concluded that treatment of P. mirabilis cells with SMP at mentioned frequency acts on its cellular activity and structure of the bacteria which can make this method is a promising one in further in vivo applications.