A first order quasi phase matched periodically poled LiNbO 3 (PPLN) for SHG with 6.5 μm period, 12 mm length, 10 mm width and 0.5 mm thickness has been successfully fabricated by applying an external electric field at room temperature from an high pulsed voltage generator. About 18 mW of CW 0.532 μm green light was obtained pumped by an 1.1 W of CW 1.064 μm Nd∶YAG laser with end coupling, which corresponds to 1.6% power conversion efficiency. The SHG normalized conversion efficiency is about 1.5% cm -1 W -1 , which shows 79% of the ideal nonlinear coefficient. A reasonable explanation of the experiment is given.