Side-pumped NdYAG rods have different radial and azimuthal thermal focal lengths. Radial and azimuthal thermal focal length are measured with rotary slit and polarized He-Ne laser. A laser oscillator is designed to produce low-loss stable oscillation in a single polarization. At the pumped power of 440 W, radially polarized beam at 31.7 W with M2=2.5 is achieved. And at the pumped power of 470 W, azimuthally polarized beam at 30.2 W with M2=2.8 is achieved. The results show that radially or azimuthally polarized beam with higher power can be achieved with mode selection of thermally induced bifocus, but the laser is sensitive to pumped power.