A corrugated tube, comprising: a body in which a plurality of peaks and a plurality of valleys are continuously alternated in a longitudinal direction of the body, and a slit formed in the body along the longitudinal direction of the body, wherein both end portions of the body between which the slit is interposed are overlapped, wherein a mark is provided to only one peak of the plurality of peaks or only one valley of the plurality of valleys at an one end portion of the both end portions and an additional mark is provided to corresponding only one peak or valley at the other end portion of the both end portions, the both end portions being brought into a fitting engagement with the marked peak or valley at the both end portions, or at least two marks are respectively provided to at least two peaks of the plurality of peaks or at least two valleys of the plurality of valleys at an one end portion of the both end portions and at least two additional marks are respectively provided to at least two corresponding peaks or valleys at the other end portion of the both end portions, the at least two marks or the at least two additional marks being arranged at an interval of at least one peak or valley in the longitudinal direction of the body, and the both end portions being respectively brought into a fitting engagement with the at least two marked peaks or valleys at the both end portions, wherein the plurality of peaks are respectively formed in an identical shape and the plurality of valleys are respectively formed in an identical shape, and wherein the length of the mark is greater than the length of the overlapped portion formed by both end portions. a body in which a plurality of peaks and a plurality of valleys are continuously alternated in a longitudinal direction of the body, and a slit formed in the body along the longitudinal direction of the body, wherein both end portions of the body between which the slit is interposed are overlapped, wherein a mark is provided to only one peak of the plurality of peaks or only one valley of the plurality of valleys at an one end portion of the both end portions and an additional mark is provided to corresponding only one peak or valley at the other end portion of the both end portions, the both end portions being brought into a fitting engagement with the marked peak or valley at the both end portions, or at least two marks are respectively provided to at least two peaks of the plurality of peaks or at least two valleys of the plurality of valleys at an one end portion of the both end portions and at least two additional marks are respectively provided to at least two corresponding peaks or valleys at the other end portion of the both end portions, the at least two marks or the at least two additional marks being arranged at an interval of at least one peak or valley in the longitudinal direction of the body, and the both end portions being respectively brought into a fitting engagement with the at least two marked peaks or valleys at the both end portions, wherein the plurality of peaks are respectively formed in an identical shape and the plurality of valleys are respectively formed in an identical shape, and wherein the length of the mark is greater than the length of the overlapped portion formed by both end portions.