The colloidal stability of titania powder in electronic ink, which contains an organic solvent of octane and a dispersant of phosphate ester, has been investigated. The concentration of phosphate ester required to stabilize the nonaqueous titania suspension agrees with that needed for monolayer adsorption. Theoretical calculations of potential energies show that the colloidal stability of organic titania suspension is caused by the steric repulsion mechanism. The results of optical properties including reflectivity and response time show that the resulting nonpolar titania suspension meets the requirements of an electronic ink for electrophoretic display.