Using equations governing the variation of the beam size and the curvature of wave front in the logrithmically saturable nonlinear media, the Gaussian-type breath mode of spatial soliton has been described in detail. With the aid of a potential method, the positive and negative signs can be assigned to the first order derivative of the beam size with respect to the propagation distance. Thus, important parameters of the breath mode, such as the beam size, curvatwre radius of the wave front, the period, etc., have been calculated.