Superpotentials of N=1 Supersymmetric Gauge Theories from M-theory

We consider brane configurations in M-theory describing N=1 supersymmetric gauge theories. Using the parametric representation of the brane configurations, we calculate the superpotentials for various cases including multiple gauge groups or fermions. For SU(n) N=1 SQCD with $N_f$ fermion case ($N_f < N_c)$, we find that the superpotential from M-theory and the gauge theory agree precisly. This gives a direct evidence of the validity of Witten's M-theory method for calculating the super potential.