To propose a structure with high strength which has only minimum notches formed at a connection portion of wooden structural members, and employs connection fittings at the connection portion.

In connection between the structural members, first a fitting A is set up by arranging a fixed plate 2 making contact with an inside of a master member 110, and a connection plate 3 orthogonally to the center of the fixed plate 2, and forming bearing plates 4 for bearing connection plates 13, 13 of a support plate 11 of a connection member 111, at lower edges of the fixed plate 2 and the connection plate 3, in one body with the plates. Then a fitting B is set up by arranging the support plate 11 abutting on an end face of the connection member 111, and both side plates 12, 12 at both edges of the support plate 11 in a manner orthogonal to the support plate 11, and forming the two connection plates 13, 13 to the center of the support plate 11 so as to be orthogonal to the same and separate the support plate 11 from the center, in one body with the plates. Then the fitting B of the connection member 111 is fitted onto the fitting A of the master member 110, and the connection plate 3 of the fitting A is superposed on the two connection plates 13, 13 of the fitting B, and they are fastened together by bolts 17, to thereby connect the master member 110 and the connection member 111 together.