A structure for multi-stage sealing of a turbine, comprising: an annular multi-stage sealing part disposed on an inner circumferential surface of a fixed body and having different heights of at least two stages, wherein the multi-stage sealing part includes: a pair of first sealing parts disposed over the inner circumferential surface of the fixed body while being spaced from each other at a predetermined interval and formed in annular shape; a pair of second sealing parts adjacently disposed to and between the pair of first sealing parts over the inner circumferential surface of the fixed body and formed in an annular shape, having a relatively lower height than the first sealing parts; and a third sealing part disposed between the pair of second sealing parts over the inner circumferential surface of the fixed body and formed in an annular shape, having a relatively higher height than the first sealing parts; and an annular multi-stage tooth part disposed to face the multi-stage sealing part over an outer circumferential surface of a rotating body and provided with a plurality of teeth, having a relative height corresponding to different heights of the multi-stage sealing part at an interval between the fixed body and the rotating body, wherein the multi-stage tooth part includes: a pair of distinct annular first tooth parts disposed to face the pair of first sealing parts over the outer circumferential surface of the rotating body and formed at a relative height corresponding to a height of the first sealing parts; a pair of distinct annular second tooth parts disposed to face the pair of second sealing parts over the outer circumferential surface of the rotating body and formed at a relative height corresponding to a height of the second sealing parts; and an annular third tooth part disposed to face the third sealing part over the outer circumferential surface of the rotating body and formed at a relative height corresponding to a height of the third sealing part; characterised in that the multi-stage sealing part further includes a first barrier groove formed in an annular shape in each of the first sealing parts at a flow direction side of a leaked fluid over the first tooth parts to hinder a flow of the leaked fluid between the fixed body and the rotating body, and/or a second barrier groove formed in an annular shape in the third sealing part at a flow direction side of a leaked fluid over the third tooth part to hinder a flow of the leaked fluid between the fixed body and the rotating body. a pair of first sealing parts disposed over the inner circumferential surface of the fixed body while being spaced from each other at a predetermined interval and formed in annular shape; a pair of second sealing parts adjacently disposed to and between the pair of first sealing parts over the inner circumferential surface of the fixed body and formed in an annular shape, having a relatively lower height than the first sealing parts; and a third sealing part disposed between the pair of second sealing parts over the inner circumferential surface of the fixed body and formed in an annular shape, having a relatively higher height than the first sealing parts; and an annular multi-stage tooth part disposed to face the multi-stage sealing part over an outer circumferential surface of a rotating body and provided with a plurality of teeth, having a relative height corresponding to different heights of the multi-stage sealing part at an interval between the fixed body and the rotating body, a pair of distinct annular first tooth parts disposed to face the pair of first sealing parts over the outer circumferential surface of the rotating body and formed at a relative height corresponding to a height of the first sealing parts; a pair of distinct annular second tooth parts disposed to face the pair of second sealing parts over the outer circumferential surface of the rotating body and formed at a relative height corresponding to a height of the second sealing parts; and an annular third tooth part disposed to face the third sealing part over the outer circumferential surface of the rotating body and formed at a relative height corresponding to a height of the third sealing part;