The present invention relates to a structure for constructing a building including girders and beams which are horizontally and vertically coupled to one another about a column. The structure includes: a
gusset plate welded to a side portion of a first girder in a direction crossing a length direction of the first girder for supporting at least one first angle connection for supporting a slab and adjusting a frame
assembly position; and a first
coupling member including a first bolt and a first nut for
coupling the first angle connection to the
gusset plate. The first nut is embedded in concrete constituting a core wall or a slab, such that the first angle connection is removable from the
gusset plate after concrete is cured in a region corresponding to the first girder. Thus,
structural stability in the preconstruction of a slab, efficiency in installing a frame to be subsequently constructed, and efficiency in installing an angle connection for supporting a slab and adjusting a frame
assembly position can be ensured. Furthermore, since the angle connection can be easily removed after slab concrete and core concrete are cured, the angle connection can be recycled, thus improving the quality of the building, decreasing the time required for construction and reducing construction costs, and enabling the building to be built more safely.