In this paper, the propagation of Gaussian laser beam in underdense and magnetized plasma has been studied. The effect of oblique external magnetic field on self-focusing of laser is specifically explored. An envelope equation governing dependence of beam-width parameter with dimensionless distance of propagation of laser is derived by adopting parabolic equation approach under WKB and paraxial approximations. It is found that increasing the angle between the laser beam magnetic field and external magnetic field decreases the self-focusing of laser propagating through plasma.