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Abstract Background and objectives: In this research, the formation of chitosan-TiO2 nanocomposite and its antibacterial effect on Escherichia coli and staphylococcus aureus was investigated Material and Methods: to study the results, we used Scanning electron microscopy (SEM) and transition electron microscopy (TEM) images, infrared (IR) spectroscopy and ultraviolet-visible. Optical Density (OD) was also measured by spectrophotometer then the effect of this nano composite, in the vicinity of aforementioned bacteria, on the sterilized gauze in solid Muller Hinton Agar and TSB liquid mediums was assessed Results: The mentioned nanocomposite was formed with the composition of 4mg/ml Chitosan concentration and 2% titanium dioxide concentration. Finally, we observed that this nanocomposite near 100% could prevent bacterial growth and in the presence of this material did not grow any bacteria. Conclusion: chitosan-Tio2 Nanocomposite can be useful on culture medium and sterilized gauze to control pathologic bacteria. Key words: nanocomposite, nanochitosan, titanium dioxide, antibacterial, sterilized gauze