Dependence of elastic properties on temperature for rutile TiO2 is investigated by the Cambridge Serial Total Energy Package (CASTEP) program in the frame of density function theory (DFT) and the quasi-harmonic Debye model. The six independent elastic constants of rutile TiO2 at high temperature are theoretically obtained for the first time. It is found that with increasing temperature, the elastic constants will decrease monotonically.Moreover, we successfully obtain the polycrystalline moduli BH and GH, as well as the Debye temperature (⊙)D.