Previously, as a means of expressing the effect of ion bombardment, we proposed an ion bombardment parameter P i based on the magnitude of the ion momentum and impingement ratio of Ar ions to metal particles. As a result the internal stress of the ferromagnetic films can be controlled by ion bombardment parameter P i . In this study, molecular mass effects with various sputtering gases such as Ar and Xe on magnetic thin films are quantitatively discussed with ion bombardment parameter P i . The Ni thin films were prepared by the D.C. magnetron sputtering process. Sputtering gases were using Argon (Ar) and Xenon (Xe). Plasma diagnostics was carried out by single Langmuir probe during the sputter deposition. The internal stress of the films varies linearly with ion bombardment parameter P i , regardless of the sputtering gas species. In addition, the magnetostrictive susceptibility of the film is also dependent on P i . Internal stress and magnetostrictive properties of Ni thin films could be controlled with ion bombardment parameter P i .