PURPOSE: To improve wear resistance by providing a surface lubricating protective layer consisting of higher fatty acid hydrazide, higher fatty acid ester and low mol.wt. isocyanate compd. on a magnetic layer.

CONSTITUTION: After the magnetic layer is formed on a nonmagnetic base, the surface lubricating protective layer consisting of the higher fatty acid hydrazide of 12W18C, higher fatty acid ester of 16W52C and further, the low mol.wt. isocyanate compd. is provided on the magnetic layer by an impregnation method. Powder dislodgment from the surface layer part of the coated film is thereby prevented and adequate lubricity is imparted to the surface layer part. Provision of the surface protective layer on the surface of the magnetic layer is executed by a method of dissolving the above-mentioned materials together with a lubricating component into an isocyanate soln. using toluene, normal hexane, etc., as a solvent to make on-part treatment and subjecting the magnetic layer to an impregnation treatment quickly after the prepn.