π- and σ-polarization laser emission in a-cut Nd∶YVO4 crystal are selectively realized with a polarization beam splitter (PBS). The difference of polarized fluorescence spectra of tetragonal Nd∶YVO4 crystal results in the performance difference between the π- and σ-polarization laser outputs. The π- and σ-polarization laser performances of a-cut Nd∶YVO4 crystal with 4F3/2 to 4I11/2 and 4F3/2 to 4I13/2 energy level transitions are investigated by rotating the laser crystal along the optical direction and active polarization selection of PBS reflected beam. When the pump power is 11 W, π-polarization laser at 1064.3 nm with output power of 5.5 W and σ-polarization laser at 1066.7 nm with output power of 4.4 W are obtained for the 4F3/2-4I11/2 energy level transition, respectively. While for the 4F3/2-4I13/2 energy level transition, π-polarization laser at 1341.8 nm with output power of 2.9 W and σ-polarization laser at 1341.8 nm with output power of 1.6 W are obtained, respectively. The experimental results show that the π-polarization laser has higher conversion efficiency and the σ-polarization laser owns longer laser spectrum for a-cut Nd∶YVO4 crystal.