The interdiffusivities of Ag/Cu multilayered films deposited on glass substrates at 298, 233 and 153 K were determined from the decay rate of the first satellite peak intensity around the 000 reflection, and analyzed in relation to structural changes in the films. The films also exhibited several satellites in a high angle region, indicating that they are not perfect single-crystal films but possess in-plane domain structures with the alternate slacking of Ag(111) and Cu(111) planes parallel to the substrate. The interdiffusivities in the films deposited at 153 K was about two orders of magnitude larger than those in the films deposited at 298 K. In this connection, the grains in the deposited films increased their sizes with increasing substrate temperature. The activation energy, 84-87 kJ mol(-1), was ascribed to the grain-boundary diffusion in the films. It is also shown that apparent interdiffusivities of the multilayers depend strongly on structural changes including grain growth due to recrystallization and thereby induced interface roughness.