To provide a magnetic recording medium capable of reducing medium noise in a high density recording system.

The magnetic recording medium comprises a non-magnetic support and a magnetic layer on the non-magnetic support, and is used for a system comprising an MR based head as a reproduction head. The magnetic layer comprises magnetic powder and binder, and has thickness of 10 to 200 nm. In the magnetic recording medium, autocorrelation length Ma in a longitudinal direction of the magnetic layer is 70 nm or less, autocorrelation length Mb in a width direction of the magnetic layer is 80 nm or less, and a ratio (Ma/Mb) of the autocorrelation length Ma in the longitudinal direction of the magnetic layer to the autocorrelation length Mb in the width direction of the magnetic layer is 0.80 to 1.20.