An improvement is proposed in the method for the preparation of a magnetic recording medium comprising a non-magnetic substrate plate of silicon and a magnetic recording layer formed on the substrate surface by the method of bias-sputtering, by which the magnetic recording layer can be imparted with an unexpectedly large coercive force. The improvement can be accomplished by the use of a silicon substrate plate which has a volume resistivity not exceeding 2 ohm-cm at room temperature. The improvement is more remarkable when the contact resistance between the silicon substrate plate and the substrate holder is kept not to exceed 10 kohm during the bias-sputtering for the formation of the magnetic recording layer on the substrate surface.