In this research, the dispersion of TiO2 nanoparticles coated by acrylic acid (AA)-plasma-polyrners in glycol solution is investigated by ultraviolet absorbency and particle size distribution measurement. The results show that the dispersion of TiO2 nanoparticles is greatly improved after AAplasma-polymer coating. It depends on the discharge parameters to a great extent and there exists an optimal dispersion value. The potentials in the DLVO theory between particles are calculated using the surface energy of nanoparticles as a main entrance. and first applied in estimation the dispersion behaviors of nanoparticles. It is found that the potential maxima in the DLVO curves match well with the optimal experimental dispersion values. This indicates the success of DLVO theory in explaining the dispersion improvement of surface-coated TiO2 nanoparticles. It also displays that the surface energy plays an important role in the dispersion behaviors of TiO2 nanoparticles. It is an effective way to improve the dispersion of nanoparticles through changing their surface energy by plasma polymer coatin.a. (c) 2005 Elsevier B.V. All rights reserved.