Colloidal titanium dioxide (TiO2) was separated from an aqueous suspension(1000 ppm) by foam flotation using cationic or anionic surfactants. The effects of surfactant dosage, suspension pH value, suspension ionic strength, and gas flow rate on the dispersed-air flotation of colloidal TiO2 were investigated. TiO2 separation was almost complete in optimum conditions. It was found that the coulombic interaction between charged TiO2 particle surfaces and ionic collectors prays a dominant role in this system. Both flotation rate and foamate volume are dependent upon the gas flow rate. Foam flotation may find application in the separation of submicron TiO2 particles in suspend-photocatalyst systems.