  We consider the effective superpotential of N=2, U(N) gauge model where N=2
supersymmetry is spontaneously broken to N=1. By the computation of loop
diagrams, we obtain a formula for the effective superpotential which is
deformed from the well-known form of the effective superpotential of N=1, U(N)
gauge model with a tree level superpotential.
