PURPOSE: To make it possible to promote joint work efficiency between reinforced concrete columns and steel framed beams and to increase rigidity of the whole building.

CONSTITUTION: Steel framed beams 10 are made to pass through column and beam joint sections of reinforced concrete columns 14 successively to arrange them in one way. Steel framed beams 12 are divided by the column and beam joint sections, and they are at right angles to the sides of the steel framed beams 10 and are butted at each other. Splice plates are arranged in a state to butt the steel framed beams 10 and 12 at each other, and the splice pates are fastened to the steel framed beams 10 and 12 with high tension bolts and nuts and are fixed to connect both steel framed beams 10 and 12. Assembly and arrangement directions of the steel framed beams passing through in succession and the divided steel framed beams are different between joint sections of the columns and beams in adjacent reinforced concrete columns 14.