The dependence of Cs saturated absorption spectra on the intensity of pumping light, especially that of the spectrum of ６２Ｓ１／２Ｆ＝４→６２Ｐ３／２Ｆ′＝５, was measured and calculated. When the pumping light and probing light were linearly polarized, the relative magnitudes of the resonance signals were calculated by solving a set of rate equations with Runge-Kutta algorithm, taking into consideration the optical pumping process and the saturation in the Zee-man sublevels of the hyperfine structure. The theoretical calculations were in good agreement with the experimental results.