In this work we model the magnetic field induced phase transformation (FIPT) of magnetic shape memory alloys (MSMAs). The working principle of such materials is described by the deformation of continua due to mechanical and magnetic forces. The cross coupling of mechanical and magnetic variables is captured by introducing nonlinear kinematics. The mechanical and magnetic constitutive equations are derived by a thermodynamic consistent way. Finally, the model prediction followed by model calibration is compared with the experimental results.