Sm3+∶SiO_2 thin film with high concentration of Sm3+ was prepared by sol-gel method using tetraethoxysilane(TEOS) as precursor and using the appropriate system of hydrolyzing-condensing and organic additives, and controlling the velocity of promoting temperature during the heat treatment. Research was done on the luminescence spectra of the gel with different concentrations of Sm3+ by fluorescence spectra analysis. The results showed that, the emission intensity of Sm3+ became stronger with increasing the doping concentration when the concentration was below 10% in the gel; the optimum excitation wavelength of Sm3+ in the gel was 473 nm, the emission peak position were at 561, 594, 643, 703 nm, which was caused from, respectively, 4G5/2-6H5/2, 4G5/2-6H7/2, 4G5/2-6H9/2, 4G5/2-6H11/2 transition of Sm3+; and the emission intensity of the gel with organic additive DMF was elevated evidently. Sm3 +: SiO 2 thin film with high concentration of Sm 3+ was prepared by sol-gel method using tetraethoxysilane (TEOS) as precursor and using the appropriate system of hydrolyzing-condensing and organic additives, and controlling the velocity of promoting temperature during the heat treatment. was done on the luminescence spectra of the gel with different concentrations of Sm3 + by fluorescence spectra analysis. The results showed that, the emission intensity of Sm3 + gave stronger with increasing the doping concentration when the concentration was below 10% in the gel; wavelength of Sm3 + in the gel was 473 nm, the emission peak position were at 561, 594, 643, 703 nm, which was caused from, respectively, 4G5 / 2-6H5 / 2, 4G5 / 2-6H7 / 2, 4G5 / 2-6H9 / 2, 4G5 / 2-6H11 / 2 transition of Sm3 +; and the emission intensity of the gel with organic additive DMF was elevated evidently.