This paper analyzes the effect of magnetic field on free convective mass transfer flow of a viscous incompressible electrically conducting fluid bounded by an oscillating porous plate in the slip flow regime with heat source in presence of a transverse magnetic field. The governing equations of the flow field are solved analytically and the expressions for the velocity, temperature, concentration distribution, skin friction and the rate of heat transfer, i.e., the heat flux in terms of Nusselts number are obtained. The effects of the flow parameters such as Hartmann number/magnetic parameter Grashof number for heat and mass transfer Schmidt number heat source parameter (S) and the Prandtl number on the flow field are analyzed with the help of figures and their salient features are discussed.