A process of producing a magnetic recording element comprising a non-magnetic support having provided thereon a subbing layer and further having provided thereon a magnetic layer comprising a ferromagnetic powder and a binder, in which the non-magnetic support is a biaxially stretched polyester and the subbing layer is formed by coating a coating solution having a solids concentration of about 0.8 to about 5 wt% comprising an amorphous linear saturated polyester resin containing an aromatic dicarboxylic acid, 10 to 50 wt% of a vinylidene chloride addition polymerizable nitrile copolymer based on the polyester resin and an organic solvent mainly composed of methyl ethyl ketone, which comprises coating the subbing solution at a temperature of about 100.degree. C. or below to provide a dry thickness of about 0.03 to about 2.0 .mu.m, drying the coated layer and then coating the magnetic recording layer thereon.