In order to have a better understanding of mechanical properties of the Nano-TiO2 antibacterial cotton fabric, FAST system was used to measure the compression, bending, shearing, extension and other low stress mechanical properties of cotton fabrics with and without treated by Nano-TiO2 antibacterial. The structural parameter and dimensional stability are also tested. Results indicated that weight, weft density, surface thickness, bending, formability, shearing and relaxation shrinkage of weft direction are all increased slightly, while shearing at warp 45°, relaxation shrinkage of warp direction and hygral expansion decreased. As a whole, most of the mechanical properties are still within the normal range and some is even better.