Natural rubber/rutile-TiO2 nanocomposites (NR/n-TiO2(R) composites) with different n-TiO2(R) contents were prepared. The n-TiO2(R) with median particle size (d50) of 73 nm was successfully prepared from commercial micron-TiO2(R) by ultrasonication. NR incorporated with n-TiO2(R) shows the good performance in mechanical properties as well as UV-protection and antibacterial properties. The mechanical performance of NR/n-TiO2(R) composites was enhanced with an increase of n-TiO2(R) content up to the optimum content at 5 phr (parts per hundred parts of rubber) and then declined. In addition, the prepared NR/n-TiO2(R) composites possess the UV-protection material. The UV-protection property of NR nanocomposites was evaluated by measuring the evolution of carbonyl absorption band from ATR-FTIR spectra, surface cracking, and mechanical properties after UV irradiation. The presence of n-TiO2(R) exhibits significant improvement in photo-degradation by UV irradiation compared to the unfilled NR. More importantly, the obtained NR/n-TiO2(R) composites demonstrate effective antibacterial property against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), the strong antibacterial property of the prepared NR nanocomposites was obtained at the only loading level of 1 phr of n-TiO2(R). The prepared NR/n-TiO2(R) composites could be used as a novel antibacterial material.