In this paper, a numerical analysis is presented for a laser beam refraction by a bounded nonlinear medium and diffraction during the beam's subsequent free--space propagation using two-dimension Gaussian input profile. The beam's steady-state transverse-field profiles in the near and far-field and power-transfer curves for passing through an aperture are studied. The results show that when beam passes through a nonlinear medium, not only beam's phase, but also its profile are undergoing change. When these two factors are taken into consideration, only under the nonlinear refractions effect the power-limiting phenomenon can be observed. In addition, if beam's intensity is below some level, limiting action effect is also existed in near-field.