A low temperature preparation of nano TiO2 using sol-gel method was proposed. The antibacterial properties of the treatment solution and the treated cotton fabrics obtained via a dip-padding process were evaluated. XRD pattern shows that the nano TiO2 produced is an anatase phase. Aqueous nano-dispersion of the nano TiO2 exhibites positive results as an antibacterial finishing agent for cotton fabrics. The treatment solution possesses antibacterial rates of over 92% and 88.9% against Escherichia coli and Bacillus subtilis,respectively. The treated fabrics are slightly downgraded but still maintained over 89% and 83% of reduction towards the same bacteria. After washing for 50 times,the antibacterial performances of the treated fabric still remains at a relatively high level,indicating the durable characteristic of nano TiO2 treatment.