A steering wheel comprising a boss (51) adapted to be fitted on a steering shaft (30) having a serration (31) composed of a plurality of teeth (31a) formed on an outer periphery thereof. Said boss (51) includes a cylindrical portion (64) with a serration (68) corresponding to said serration (31) on an inner periphery thereof, and a yoke portion (65) provided integral with said cylindrical portion (64) having through holes (36, 37) formed substantially at both ends thereof, wherein at least one (36) of said through holes (36, 37) being formed with an internal thread. A steering wheel body 1 including a ring core bar (5), spoke core bars (6A, 6B, 6C), sheaths (7a, 7b) covering said core bars (5, 6A, 6B, 6C), and a pad (3) formed integrally with said sheaths (7a, 7b) and located in a substantially central upper portion of a ring (2), part of said spoke core bars (6A, 6B, 6C) being connected to said boss (51). A bolt (81) with an external thread formed at least approximately on an end thereof being adapted to be screwed into said through holes (36, 37) so as to fix the boss (51), to which said steering wheel body (1) is connected, wherein on said steering shaft (30) at least said spoke core bars (6A, 6B, 6C) being made of die-cast aluminum. Said boss (51) comprises a boss body (66) composed of said cylindrical portion (64) and said yoke portion (65), and a boss plate (53) fixed by welding to said boss body (66) and having a larger area than said yoke portion (65), and the extreme edge of said boss plate (53) is embedded in said spoke core bars (6A, 6B, 6C). Or said boss (51) comprises said boss body (66) including said cylindrical portion (64) and said yoke portion (65), and a flange (64a, 52) formed integrally with said boss body (66) and having a larger area than said yoke portion (65), and said flange (64, 52) is embedded in said spoke core bars (6A, 6B, 6C). A steering wheel boss structure comprising a boss (28) adapted to be fixedly fitted on a steering shaft (30) and having at least a generally cylindrical shape, wherein a plurality of spoke core bars (6A, 6B, 6C) made of die-cast aluminum and extending from an annular ring core bar (5) toward approximately the center thereof, and a connecting portion (71) formed integrally with said spoke core bars (6B, 6C) so as to connect said spoke core bars (6B, 6C) to one another while being connected to said boss (28). Said connecting portion 71 is formed therein with a tapered through hole (72), wherein said boss 28 is press-fitted in said through hole (72), and at least a tapered distal end of said boss (28) is increased in diameter so that said boss (28) is fixed to said connecting portion.