In This Paper We Consist the Problem of Couette Flow Between Two Horizontal Parallel Porous Flat Plates of an Electrically Conducting Viscous Incompressible Fluid. the Stationary Plate Is Subjected to A Transverse Sinusoidal Injection of the Fluid and Its Corresponding Removal By The Constant Suction Through the Other Plate, In Uniform Motion and Because Of Injection Velocity The Flow Becomes Three-Dimensional. a Magnetic Field Of Uniform Strength Is Applied Normal to the Planes of the Plates. the Effect Of Injection/Suction Velocity and the Magnetic Field on the Flow Field, Skin Friction And Heat Transfer Are Reported and Discussed In Detail.