Abstract: The beam quality, wavelength and polarization are the basic properties of lasers, which have great effect upon laser materials processing. The following topics about the role of laser beam performance in laser materials processing are discussed:1. The demand of laser materials processing on the beam quality and the evaluation of the beam quality. 2.The influence of the beam quality, wavelength and beam diameter on the process of the laser propagation, focusing and its processing ability.3. The energy coupling mechanisms depended on the power density and the influence of the beam wavelength on the coupling efficiency. 4. The polarization of laser beams and the applications of polarized laser beams.