A steel pipe for high strength line pipe use excellent in hydrogen induced crack resistance, wherein the steel pipe is constructed from a steel plate consisting of, by mass%, C: 0.02 to 0.08%, Si: 0.01 to 0.5%, Mn: 1.2 to 1.8%, Nb: 0.001 to 0.10%, Ca: 0.0005 to 0.0050%, N: 0.0010 to 0.0060%, O: 0.0001 to 0.0035%, and optionally further containing, by mass%, one or more of Ni: 0.01 to 2.0%, Cu: 0.01 to 1.0%, Cr: 0.01 to 1.0%, Mo: 0.01 to 0.60%, W: 0.01 to 1.0%, V: 0.01 to 0.10%, Zr: 0.0001 to 0.050%, Ta: 0.0001 to 0.050%, B: 0.0001 to 0.0020%, REM: 0.0001 to 0.01%, Mg: 0.0001 to 0.01%, Y: 0.0001 to 0.005%, Hf: 0.0001 to 0.005%, and Re: 0.0001 to 0.005%, and a balance consisting of Fe and unavoidable impurities, wherein contents are restricted to P: 0.01% or less, S: 0.0020% or less, Al: 0.030% or less, and Ti: 0.030% or less, and contents of S and Ca satisfy S/Ca<0.5; the steel plate satisfying: maximum Mn segregation ratio: 2.0 or less, Nb segregation ratio: 4.0 or less, Ti segregation ratio: 4.0 or less, length of center-porosities at centerline segregation: 0.1 mm or less, maximum hardness of centerline segregation: 300 Hv or less, maximum hardness of surface layer region from topmost surface of two front and back plate surfaces down to depth of 5 mm: 300Hv or less, and a total fraction of polygonal ferrite and deformed ferrite with an aspect ratio of 3 or more at surface layer region from topmost surface of two front and back plate surfaces down to depth of 5 mm: 0.1 to 20%, wherein the structure other than the polygonal ferrite and the deformed ferrite is bainite and/or acicular ferrite; wherein the total fraction of polygonal ferrite and deformed ferrite with an aspect ratio of 3 or more at surface layer region from topmost surface of two front and back plate surfaces down to depth of 5 mm is measured by taking five 200X optical micrographs in surfaces in plate thickness direction and rolling direction, measuring the area ratios of the polygonal ferrite and deformed ferrite, and calculating the total fraction of these, and thickness "t" [mm] of the steel plate and outside diameter D [mm] of the steel pipe after pipemaking satisfying t≥25 and t/D≥0.035. maximum Mn segregation ratio: 2.0 or less, Nb segregation ratio: 4.0 or less, Ti segregation ratio: 4.0 or less, length of center-porosities at centerline segregation: 0.1 mm or less, maximum hardness of centerline segregation: 300 Hv or less, maximum hardness of surface layer region from topmost surface of two front and back plate surfaces down to depth of 5 mm: 300Hv or less, and a total fraction of polygonal ferrite and deformed ferrite with an aspect ratio of 3 or more at surface layer region from topmost surface of two front and back plate surfaces down to depth of 5 mm: 0.1 to 20%, wherein the structure other than the polygonal ferrite and the deformed ferrite is bainite and/or acicular ferrite; wherein the total fraction of polygonal ferrite and deformed ferrite with an aspect ratio of 3 or more at surface layer region from topmost surface of two front and back plate surfaces down to depth of 5 mm is measured by taking five 200X optical micrographs in surfaces in plate thickness direction and rolling direction, measuring the area ratios of the polygonal ferrite and deformed ferrite, and calculating the total fraction of these, and thickness "t" [mm] of the steel plate and outside diameter D [mm] of the steel pipe after pipemaking satisfying t≥25 and t/D≥0.035. t≥25 and t/D≥0.035. <EOS>