6.5 mol.% MgO-doped LiNbO3 (MgLN) single crystal has been grown by the Czochralski technique. The MgO-doped crystal shows a shift in the absorption edge towards shorter wavelengths and a three orders of magnitude increase in the photorefractive damage resistance compared to the congruent LiNbO3 crystal (CLN). This material has been periodically poled (PP) at room temperature by applying electric field, and the coercive field is 5 KV/mm, which is about 1/4 of that for congruent LiNbO3. Periodic poling of 1 mm thick 6.5 mol.% MgO-doped LiNbO3 substrates has been successfully performed and its operation in a femtosecond second-harmonic generation at room temperature. The performance of quasi-phase-matched second harmonic generation with a 1mm thick PP MgO:LN was compared with that of the second harmonic generation with the PP CLN at room temperature. The PP MgO:LN exhibited better performance.