In the present paper, we have examined the sensitiveness of light absorption for self-focusing of Gaussian laser beam in plasma. By introducing dielectric function of plasma under ponderomotive and weakly relativistic regime, we have established the differential equation for beam-width parameter by using parabolic equation approach under Wentzel-Kramers-Brillouin and paraxial approximations and solved it numerically. In order to incorporate the sensitiveness of light absorption for self-focusing, behavior of normalized beam-width parameter; plasma density distribution with dimensionless distance of propagation is presented graphically and discussed. Numerical analysis shows that light absorption plays a vital role in self-focusing of laser beam in plasma under weakly relativistic and ponderomotive regime and gives reasonably interesting results.