A charge generation of particles due to an acid-base dissociation in non-polar solvent is essential for liquid toners used in electrophotography. In this paper, a charge generation and a dispersion stability of acrylic polymer particles including base groups by an interaction with acid / base dispersing polymers modified with silicone groups in silicone oil are discussed. The dynamic mobility and the dispersion stability of the particles are measured by electrokinetic sonic amplitude methods (ESA) and visually observed by a high-speed video camera. From these observations, it is suggested that the charge generation at the surface of particles is affected by the acid-base dissociation in the silicone oil. As evidence, the mobility of the particles increases responding to an increase in acid polymer concentration solved in silicone oil. In conclusion, a suitable concentration of the acid / base dispersing polymer which makes the particle higher mobility is presented.