Abstarct: In this research, we investigated the propagation of intense laser pulses in underdense plasma and obtained electron density, dielectric permeability, and beam width parameters changes in the presence of ponderomotive force, external magnetic field, and density and temperature inhomogeneity. It was found that, with increasing ponderomotive force, the density of electrons on the beam axis decreases, and as a result, the dielectric permittivity increases. Examining the density and temperature inhomogeneous, we found that there is a temperature turning point, where the behavior of the beam width parameter varies around this point. We also found for density inhomogeneous changes that, like temperature, there is a density turning point for density. Finally, we obtain the effect of the external magnetic field on the beam width parameter. It was found that with increasing external magnetic field, the self-focusing phenomenon in plasma changes from focusing to de-focusing.