The colloidal stabilization of nano-sized zinc oxide suspensions with maleic anhydride sodium salt copolymer is examined to understand the primary mechanism of dispersion. FTIR spectroscopic data provided evidence in support of hydrogen bonding and chemical interaction in the case of the MA-Na copolymer/ZnO system. The suspension stability was characterized by sedimentation tests and TEM method. The copolymer was found to stabilize the suspension of ZnO nanoparticles through electrosteric repulsion. Influences of factors such as pH and the copolymer concentration on the colloidal stability of aqueous suspension were investigated. The copolymer at high pH of the solution provided more effective degree of sustained particle dispersion. The adsorbed MA-Na copolymer provided a good stabilization under the saturated adsorption amount, while the excess copolymer flocculated the dispersed system.