A magnetic recording medium has a substrate made of a nonmetal nonmagnetic material whose coefficient of linear expansion lies within a range from 0.000013/deg to 0.0001/deg. A magnetic layer is formed on the substrate as a thin polycrystalline film or a thin amorphous film. The magnetic layer has Co as a main component, which exhibits a negative magnetostrictive constant so that its coercive force rises in the direction of compressive strain. The magnetic layer is subjected to an in-plane compressive strain from the substrate due to a difference between the coefficient of thermal expansion of the substrate and the magnetic layer so that high coercivity is obtained in the magnetic layer.
