A combined oil ring to be fitted in an oil ring groove of a piston, comprising: a pair of upper and lower plate-like circular side rails; and a spacer expander arranged between the pair of upper and lower side rails, the spacer expander including: a large number of upper pieces and lower pieces that are alternately arranged in a circumferential direction so as to be spaced apart in an axial direction and the circumferential direction; coupling pieces that respectively couple the adjacent upper pieces and lower pieces; and ear parts that are each formed so as to erect in an inner circumferential end portion of each of the upper pieces and the lower pieces, and serve to push the side rails, at least one of an upper surface of each upper piece and a lower surface of each lower piece having a groove formed thereon, each ear part having, formed therein, a through-hole with which the groove is communicated, wherein the combined oil ring is characterized in that the through-hole is formed such that a distance A along the axial direction between one of an upper surface and a lower surface of each ear part at a top thereof and a deepest portion of the groove is equal to or more than 0.22 mm, in that a plate thickness T of the spacer expander is set to 0.17 to 0.28 mm, and in that a ratio A/T of: the distance along the axial direction between one of the upper surface and the lower surface of each ear part at the top thereof and the deepest portion of the groove; to the plate thickness of the spacer expander is 0.77 to 3.00. a pair of upper and lower plate-like circular side rails; and a spacer expander arranged between the pair of upper and lower side rails, the spacer expander including: a large number of upper pieces and lower pieces that are alternately arranged in a circumferential direction so as to be spaced apart in an axial direction and the circumferential direction; coupling pieces that respectively couple the adjacent upper pieces and lower pieces; and ear parts that are each formed so as to erect in an inner circumferential end portion of each of the upper pieces and the lower pieces, and serve to push the side rails, a large number of upper pieces and lower pieces that are alternately arranged in a circumferential direction so as to be spaced apart in an axial direction and the circumferential direction; coupling pieces that respectively couple the adjacent upper pieces and lower pieces; and ear parts that are each formed so as to erect in an inner circumferential end portion of each of the upper pieces and the lower pieces, and serve to push the side rails, at least one of an upper surface of each upper piece and a lower surface of each lower piece having a groove formed thereon, each ear part having, formed therein, a through-hole with which the groove is communicated, wherein the combined oil ring is characterized in that the through-hole is formed such that a distance A along the axial direction between one of an upper surface and a lower surface of each ear part at a top thereof and a deepest portion of the groove is equal to or more than 0.22 mm, in that a plate thickness T of the spacer expander is set to 0.17 to 0.28 mm, and in that a ratio A/T of: the distance along the axial direction between one of the upper surface and the lower surface of each ear part at the top thereof and the deepest portion of the groove; to the plate thickness of the spacer expander is 0.77 to 3.00.