Four different formulas of the Eu3+ doped TiO2 nano-crystals are prepared by the sol-gel method, using tetrabutyl titanate as the precursor. The morphology, composition and properties of the luminous samples are characterized by the SEM, EDS and PL spectra. And also the effects and mechanism of annealing temperature, mole fraction of the Eu3+ ions doped and the quantity of ethanol on the luminous intensity are analyzed respectively. The results show that the samples are homogeneusly doping, and the particle size is about 30~80 nm. The EDS spectra show that the Ti∶O atomic ratio is not based on the number of stoichiometric TiO2 to meet the ratio 1∶2, for the formation of Ti-O-Ti bond in TiO2, Eu3 + is likely to replace the Ti4+, at the same time the oxygen vacancies is formed, which indicates that the rare earth of Eu3+ entered into TiO2 lattices. The PL spectra of nano-crystal TiO2∶Eu3+ show the strongest red emission intensity at 614 nm(5D0→7F2), simultaneously, the sample emission peak at 593 nm(5D0→7F1), which is classified to the magnetic dipole transition. In addition, annealing temperature and the quantity of ethanol have important effects on the emission intensity.