By utilizing the principle of polarization-selective grating mirrors, a 35-layer circular grating mirror, with 1000 nm period and 70 nm groove depth, has been designed and fabricated. The grating mirror is placed in a laser diode pumped Nd:YAG rod laser system as the cavity mirror. After optimizing the laser system, we get a radially polarized beam, of which the degree of radial polarization and the power are 97% and 13.4 W, respectively.