Using transformation technology, laser beams with different shape and spatial intensity distribution are gained. Therefore, some required hardened results such as homogeneous hardened layers could be obtained. The quality of laser surface hardening(LSH) is depended strongly on the intensity distribution. Required surface temperature field and hardened layer are formed by special beam intensity of laser hardening. Laser beams applied in surface hardening include Gaussian beam, flat-topped rectangular beam, curved rectangular beam and array spot beam. Inverse method is required to design the intensity distribution profile corresponding to the hardened quality. The trend of LSH with determined intensity distribution is put forward.