Computer simulation of Co₈₂ Gd₁₈ film deposition on a planer substrate has been conducted to elucidate the process of film formation by sputtering. In the simulation, Co and Gd atoms were taken to be Lennard-Jones particles having atomic diameters of 2.50Å and 3.40Å, respectively. Five film formation processes were simulated, and the resultant strucure factors of the 305-atom deposits were compared with an experimental reduced interference function F(k) and a reduced radial distribution function G(r). Among the five structures obtained, only one reproduced the experimental F(k) and G(r) with fair accuracy. In the simulated deposition of this model, Co-Co as well as Co-Gd atom pairs has been formed and deposited on the surface.