The dispersion behavior of fine particles in water, ethanol and kerosene media has been studied by sedimentation analysis. It was found that the dispersion behavior of fine particles complies with the principle of polarity compatibility. The dispersion effect can be improved when the surface polarity of particles approaches that of liquid media. Adsorption models of oleic acid on the surface of particles in water and ethanol are proposed. (C) 2003 Published by Elsevier B.V.