A magnetic recording medium has, on a nonmagnetic support, a magnetic layer consisting mainly of an acicular iron oxide magnetic powder and a binder. In order to improve the S/N ratio, a fine magnetic powder having a specific surface area as determined by the BET method, of not less than 35 m.sup.2 /g is used. In order to improve the dispersibility of the magnetic powder and to improve the squareness ratio and durability thereof, the binder contains a resin which has a molecular weight of not more than 50,000 and has at least one polar group selected from the group consisting of polar groups having the general formulas: ##STR1## (wherein M is hydrogen, lithium, sodium or potassium; and M.sub.1 and M.sub.2 are hydrogen, lithium, sodium, potassium or alkyl groups.)