The pumping laser pulse of narrow pulse-width together with its leading edge shape as well as parameters of the two-cell stimulated-Brillouin-scattering (SBS) systems have an influence on the SBS pulse intensity and conversion efficiency. Two narrow pulses with different leading edges pump the two-cell systems simultaneouly. Bu changing the amplifier-cell length and the focal length, different conversion efficiencyies were observed. The two SBS pulses results are analyzed with transient seeded Stockes in the amplifier-cell. A method to design the two-cell systems is proposed.