Abstract: Amorphous Eu₂O₃ and In-doped Eu₂O₃ was prepared by an aqueous sol-gel method. To investigate the luminescence properties of the amorphous Eu₂O₃ and In-doped Eu₂O_3, their optical properties were studied by XRD, PL, and fluorescence. Emission due to the ⁵D₀ →⁷F_<em>J(J= 0, 1, 2, 4, 5, 6) transitions of Eu³⁺ ions were observed. The dominant transition was observed to be the ⁵D₀→⁷F₂ emission of Eu³⁺. Properties of the as-prepared samples were different with changes in the amount of In³⁺. PL peak positions were unchanged with the changes in the amount of In³⁺ at room temperatures. The intensity of the luminescence changed with the changes in the amount of In³⁺. There were appeared strong intensity of the luminescence at 615nm and 619nm for all samples annealed at 600℃. Intensity of the luminescence at 615 nm became stronger and the intensity of luminescence at 619 nm became weaker with the increases of amount of In³⁺. The intensity of the luminescence is the strongest for little In³⁺ doped(x_In=0.01) amorphous Eu₂O₃.