Congruent Sr 0.61Ba0.39Nb2O6 (SBN:61) crystals doped with Ce and/or Eu have been grown by Czochralski method, and characterized by transmission, reflection, emission, and excitation spectra. Both of the two doping ions substitute for Sr2+ or Ba2+ and occupy Al or Az sites in SBN. Ce3+ and EU3+ are the dominant charge states. Compared with the undoped SBN, both Ce and Eu doped crystals exhibit shifts of the fundamental absorption edge towards the longer wavelength direction. Lattice distortion caused by the doping ions has been characterized by the change of lattice parameters obtained from X-ray diffraction patterns, and the width of exponential absorption band tail. In the Ce and Eu double-doped crystal, serious lattice distortion, location shift of EU3+ absorption, excitation, and emission peaks, and emission quenching of Eu3+ ions have been observed. The doping defects and their effects on the lattice and energy band structures are also discussed.