Abstract: A new method was presented to deposit Cu thin films with applied magnet under substrate in the magnetron sputtering apparatus.It is found that the films’ surface morphology are different with the samples prepared by the normal methods.During deposition,it is also found the glow of the discharged plasma became very bright.With the same input power,self-bias voltage became smaller comparing with the magnetron sputter.The reason of the phenomenon was discussed and they were caused by the effect of the magnetic mirror on ions in the space.