A magnetic recording medium having a heat shrinkage ratio of not higher than 1% and comprising a nonmagnetic support in the form of a tape which has a heat shrinkage ratio of not higher than 1.8%, a Young's modulus of 450 to 650 kg/mm.sup.2 in the longitudinal direction and a Young's modulus of 450 to 550 kg/mm.sup.2 in the width direction, and a magnetic recording layer provided on the support which comprises a binder and a ferromagnetic powder dispersed therein and has a squareness ratio of not less than 0.89. All the heat shrinkage ratios are values determined after being allowed to stand at 110.degree. C. for 4 hours.