  We study the supersymmetric leptogenesis via $LH_{u}$ flat direction with a
gauged $U(1)_{B-L}$ symmetry. We find that the resultant baryon asymmetry is
enhanced compared with the case without a gauged $U(1)_{B-L}$ symmetry. The
baryon asymmetry is proportional to the reheating temperature of inflation, but
it is independent of the gravitino mass. If high reheating temperatures of
inflation $T_{R}\sim 10^{10}\GEV$ are available, the mass of the lightest
neutrino, $m_{\nu 1}\sim 10^{-4}\EV$, is small enough to explain the baryon
asymmetry in the present universe. Furthermore, the gravitino mass independence
of the produced baryon asymmetry allows us to explain the present baryon
asymmetry even in low energy SUSY breaking scenarios such as gauge-mediation
models. Our leptogenesis scenario is also very special in the sense that it is
completely free from the serious Q-ball formation problem.
