PURPOSE: To facilitate connection of a column and beam steels, and to reduce cost and shorten term of works while improving safety.

CONSTITUTION: A connecting unit 23, formed of a steel pipe ring 24, connecting brackets 25 and tie-hoops 26, is prefabricated. The connecting unit 23 is placed over a column steel 21, erected in a specified position, and positioning of the connecting unit 23 is made after it is lowered from the upper end of the column steel 21. After the connecting unit 23 is fixed to the column steel 21, beam steels 22 are connected to the connecting unit 23 with joint plates 28 and bolts. Then, column main reinforcements 3 are arranged and concrete 5 is placed, and thereby a column 20 and the beam steels 22 are connected together.