Ni-Mn-Ga ferromagnetic shape memory thin films have been deposited on P type Si（100）substrates by means of RF magnetron sputtering technique.The results show that RF sputtering power Ni-Mn-Ga film composition and morphology are significantly affected.Ni content increases with the sputtering power is first increased and then decreased.Mn content is decreased and then increased the trend.Ga content almost linearly decreasing trend.The electron concentration（e/a）of the film changes little.Reference to the British National Physical Laboratory data on Ar gas sputtering yields for different elements of data

from the theoretical analysis the deviation of film composition.