Lithium niobate crystals with different MgO-doped concentrations were processed by vapor transport equilibration technique and the composition Xc ([Li]/[Li+Nb]) of the prepared crystals was found to be 49.9 mol.%. A blue shift from 320 to 306 nm for processed crystals was found and the processed crystals doped 2 mol.% MgO increased the photorefractive damage resistance by at least 4 orders of magnitude compared with congruent crystal. By applying an external electric field of 3.5 kV/min, a periodically poled domain structure was obtained in the doped MgO (2mol.%) near-stoichiomerit LiNbO3 crystals.