Membrane technology has been extensively used for water and wastewater treatment. Hydrophilic polymer membranes such as cellulose acetate (CA) are good choice for membrane separation process due to moderate flux and excellent hydrophilicity, which lead to enhance the anti-fouling property. In this study, membranes were prepared by pristine and polyethylene glycol (PEG) -grafted nanodiamond (ND) embedded in CA as matrix polymer, and characterized by tensile and antibacterial test. Results shown the improvement in mechanical and antibacterial property of CA membrane by incorporation of nanoparticles into matrix of CA membrane.