A structural study, using TGA-DSC analysis, X-ray diffraction, Raman scattering and FT Infrared absorption, is performed on mixed titanium lithium oxide with 20% of lithium prepared by sol-gel process. The structure is investigated as a function of the annealing temperature. At low temperatures the sample is in the anatase phase and transforms to the rutile phase near 500degreesC. The crystallite size of rutile TiO2 increases from 40 to 100 nm as the temperature increases. However the size increase presents some discontinuity at temperature around 600degreesC. At thermal treatment temperatures from 500degreesC to 850degreesC the presence of LiTi2O4 in the sample is clearly observed. Finally at 1000degreesC the sample is composed by a mixture of rutile TiO2 and Li2Ti3O7.