The RuO2-glass interaction has been studied by analyzing the growth of RuO2 particles in glasses. The size of RuO2 particles was determined by TEM and X-ray line broadening. The RuO2/glass interfacial energy was evaluated by spreading and penetration experiments. Changes in size and shape of RuO2 particles indicated that coarsening proceeded by the diffusion-controlled dissolution-precipitation process. The growth rate of RuO2 particles at temperatures giving the same viscosity was dependent on the glass composition. Kinetics of the Ostwald ripening and values of glass surface energy implied that the solubility of RuO2 in glass is a critical factor. Results indicated that, the solubility of RuO2 in glass decreases with increasing PbO content and with increasing SiO2 substitution for B2O3. Dissolution of Al2O3 from substrate retarded the Ostwald ripening.