A Note on Superfields and Noncommutative Geometry

We consider the supersymmetric field theories on the noncommutative $R^4$using the superspace formalism on the commutative space. The terms depend onthe parameter of the noncommutativity $\Theta$ are regarded as theinteractions. In this way it is constructed that the N=1 supersymmetric actionfor the U(N) vector multiplets and chiral multiplets of the fundamental,anti-fundamental and adjoint representations of the gauge group. It is alsoobtained that the action for vector multiplets of the products gauge group andits bi-fundamental matters. We discuss the problem of the derivative terms ofthe auxiliary fields