A series of Ca‐doped YIG films in which the atomic ratio of Ca to Y in the melt varied from 0 to 1.18 were grown. Resistivities of the virgin state of these films were measured. The dependence of the linewidth when the field is applied at 30° from the film normal on the Ca/Y atomic ratio was found to be linear and the dependence of the field isappliednormalto the film surface. These are clear indications of the eddy current damping mechanism. The linewidth contribution due to this mechanism is given by &Dgr;He.c.= (2&pgr;/c2&ggr;) &sgr;A&ohgr;2where &sgr; is the conductivity, A is the disc area, &ohgr; is the radial frequency and the magnetic field is applied normal to the film plane.