Effects of atmospheres and adidtives on the grain growth of TiO2 ceramics were investigated. In the range of 1300~140$0^{circ}C$, grain growth was increased in CO2 as compared with O2 atmosphere and the grain boundary migration activation energy was lower than the diffusion activation energy of oxygen ion in TiO2. Also, in the case of addition of oxides, the grain growth was increased by oxides acting as a acceptor andinhibited by oxides acting as a donor. From the above results, when the oxygen vacancy concentration was increased, the intrinsic grain boundary mobility was increased and the pore drag force was decreased due to the rapid densification. Also it seems that the pore was migrated by the surface diffusion rather than lattice diffusion.