Magnetic recording medium

A magnetic recording medium prepared by applying onto a non-magnetic support a magnetic coating material containing fine ferromagnetic particles dispersed in a binder and curing said magnetic coating material, characterized in that said binder comprises a thermoplastic resin selected from polyester resins and polyurethane resins or a radiation-curable resin selected from polyester acrylate resins and polyurethane acrylate resins wherein there is chemically bonded as a comonomer in the polymer chain of the resin, at least one phosphorus compound represented by the following formulas:

• ##STR9## wherein each of X and Y is an ester-forming functional group, R.sub.1 is a trivalent hydrocarbon group having 3-10 carbon atoms, R.sub.2 is a member selected from the class consisting of alkyl groups having 1-12 carbon atoms, cycloalkyl groups, aryl groups, alkoxy groups having 1-12 carbon atoms, cycloalkoxy groups and aryloxy groups wherein the aryl group may be substituted with a halogen atom, a hydroxyl group, a group of the formula --OM', wherein M' represents an alkali metal, or an amino group, each of R.sub.3 and R.sub.4 is a member selected from the class consisting of alkylene groups having 1-12 carbon atoms, cycloalkylene groups, arylene groups and groups of the formula --CH.sub.z -(OR.sub.5)m wherein R.sub.5 is a group selected from the class consisting of alkylene groups having 1-12 carbon atoms, cycloalkylene groups and arylene groups, and m is any number from 1 to 4, and M represents an alkali metal, hydrogen atom, an alkyl group having 1-4 carbon atoms or an amino group, the content of the phosphorus compound in the resin being 100 ppm to 20,000 ppm calculated as phosphorus atoms.