The congruent lithium tantalate (LiTaO3) single crystals doubly-doped with Nd 3+ and In 3+ ions are grown by the Czochralski method. The ultraviolet-visible absorption spectra of these single crystals are measured, the defect structures of these single crystals are analyzed, and the threshold of the doping concentration of In 3+ ion is obtained. When the doping concentration of In 3+ ion reaches this threshold, the optical damage resistance ability of In∶Nd∶LiTaO3 crystals enhances significantly. The replacement of the anti-site T aLi4+ by In 3+ ions enhances the photo-conductivity of crystals and weakens the photorefractive effect. The full width at half maximum of the absorption peak of In∶Nd∶LiTaO3 crystals at the wavelength of 0.808 μm is 15 nm, and the absorption cross-section is 5.26×10 -21 cm 2. With a 0.808 μm semiconductor laser as the pumping source, a strong luminescence band of Nd 3+ ions appears at the wavelength of 1.06 μm. These study results show that the In∶Nd∶LiTaO3 crystals can be applied in high power photonic or integrated optoelectronic devices as the multi-functional crystals.