A fixture for buckets for a turbine, comprising: a rotor wheel that includes: a plurality of dovetail grooves extending in axial direction of a rotor and disposed to be spaced apart from each other along a circumferential direction of the rotor, and a plurality of platform seats disposed between the dovetail grooves, each including a first insertion groove extending in the circumferential direction; buckets each including: a platform that inserts into one of the dovetail grooves, and a base platform disposed on an upper surface of the platform, the base platform including a second insertion groove extending in the circumferential direction and located at a position that faces the first insertion groove; a first fixture inserted into an internal area defined by the first and second insertion grooves (122, 201); a second fixture operable to be inserted into the internal area defined by the first and second insertion grooves (122, 201) of a final bucket to fix the final bucket among buckets mounted on the rotor wheel; and an auxiliary fixture operable to be inserted into an opening hole formed in the base platform of the final bucket and facing the second fixture; wherein the auxiliary fixture is further inserted into a third insertion groove of the second fixture; characterized by: an adjustment member operable to be inserted in a gap between the platform seat and the lower surface of the base platform to adjust the position of the second fixture to allow insertion of the auxiliary fixture into the second fixture. a rotor wheel that includes: a plurality of dovetail grooves extending in axial direction of a rotor and disposed to be spaced apart from each other along a circumferential direction of the rotor, and a plurality of platform seats disposed between the dovetail grooves, each including a first insertion groove extending in the circumferential direction; a plurality of dovetail grooves extending in axial direction of a rotor and disposed to be spaced apart from each other along a circumferential direction of the rotor, and a plurality of platform seats disposed between the dovetail grooves, each including a first insertion groove extending in the circumferential direction; buckets each including: a platform that inserts into one of the dovetail grooves, and a base platform disposed on an upper surface of the platform, the base platform including a second insertion groove extending in the circumferential direction and located at a position that faces the first insertion groove; a platform that inserts into one of the dovetail grooves, and a base platform disposed on an upper surface of the platform, the base platform including a second insertion groove extending in the circumferential direction and located at a position that faces the first insertion groove; a first fixture inserted into an internal area defined by the first and second insertion grooves (122, 201); a second fixture operable to be inserted into the internal area defined by the first and second insertion grooves (122, 201) of a final bucket to fix the final bucket among buckets mounted on the rotor wheel; and an auxiliary fixture operable to be inserted into an opening hole formed in the base platform of the final bucket and facing the second fixture; wherein the auxiliary fixture is further inserted into a third insertion groove of the second fixture;