MgxNi thin films have been prepared by an RF-DC coupled magnetron sputtering technique. RF power and DC bias were simultaneously applied to the target in order to control the incident ion energy on the target. When a low RF power and DC bias are applied simultaneously to the target, the glow discharge takes place at a low DC bias and the target DC current increases smoothly as compared with the DC mode magnetron case. The values of the film compositional ratio Ni/Mg were obtained in the range of 1.19-0.56 at target DC bias voltages of - 50- -200 V without changing the target area ratio of Ni to Mg. The crystalline structure of Mg,Ni films is influenced by the target DC bias.