A magnetic recording medium composed of a non-magnetic base film; a
non-magnetic undercoat layer formed on the non-magnetic base film,
including a binder resin and non-magnetic acicular black iron-based
composite particles; and a magnetic coating film comprising a binder resin
and magnetic particles. The non-magnetic acicular black iron-based
composite particles having an average major axis diameter of about 0.011
to 0.35 .mu.m, and are composed of acicular hematite particles or acicular
iron oxide hydroxide particles (as core particles) having an average major
axis diameter of 0.01 to 0.3 .mu.m; a coating layer formed on the surface
of the core particles of a specific organosilicon compound; and a single
carbon black coat formed on the coating layer in an amount of 21 to 50
parts by weight based on 100 parts by weight of the core particles.
