[Problem] To provide a piston ring having excellent abrasion resistance to an aluminum alloy cylinder or cylinder liner that is a mating material and being capable of decreasing abrasion of the mating material. [Means to Solve The Problem] A piston ring 10 comprising a hard carbon coating 14 formed on an outer peripheral surface 10a, wherein the hard carbon coating contains 0.5 atom% or more to less than 5 atom% of W.