The study was the effectiveness of the microbial activity by using titanium dioxide nanoparticles which are prepared by using laser ablation of titanium pellet immersed in de-ionzed water. Palsed Nd: YAG laser with 1064nm wavelength and laser energy 250 mJ was used to irradiate the target for ablation time 15 min, 200 pulses. Where studied synthetic characteristics of the sample prepared using the X-ray diffraction pattern of nanoparticles proved the presence Alatanas planes. A scanning electron microscope measurement appearance Tio2 nanoparticle of structures with cube shapes , while the results of Zeta potential was the values being equal to (34) are located within the range of suspension potential Stability. The results of antimicrobial activity of Tio2 nanoparticle against bacterial stratin S.aureus, C .albicans, and E.coli with antibiotic at concentration .1000 mg/ml (AMC, DO10 and CN10) using well diffusion assay showed. The best concentration of 1000 mg /ml of antibiotics give us with dioxide nanoparticles to inhibition bacterial growth .The results showed that the nanoparticles with antibiotics inhibition the growth of S.aureus then C.albicans which is more sensitive than E.coli .Our results showed that dioxide nanoparticles have synergistic effect with (CN10& DO10) .And there is no any synergistic effect with (AMC).