The effects of ground state depletion of atoms on the characteristics of stimulated Raman scattering in metal vapors are studied by simultaniously solving the rate-equation of the atom energy levels related in the Raman scattering, and the equations describing the energy-conversion from the focused pump laser pulses to the Raman down-converted pulses. The ground state of metal atoms are depleted most strongly in the regions near the focal spots of the pump beams because of the higher intensities of light and smaller available medium volume in tliosa ；regions. This will result in tlia unsymmetrical shapes of tho Raman-shifted pulses for the front and rear edges, and will reduce the energy-conversion efficiency.