Sufficient yield strength is achieved against tensile, compressive and shearing forces working on
steel frame columns and
steel frame girders by using simply configured connective fittings to reduce costs and construction periods. For this purpose, a connective structure of highly rigid
steel frame columns and steel frame girders formed by connecting steel frame columns and steel frame girders each having a web part and
flange parts with connective fittings is provided. Each of the connective fittings has a bottom plate part and, on a surface of the bottom plate part, side plate parts which rise at a substantially right angle to the bottom plate part and have inserting areas extending farther than a tip of the bottom plate part in the state of rising at the substantially right angle. On the other hand, slit holes are formed in the
flange parts of the steel frame columns in the area where the
flange parts cross the flange parts of the steel frame girders, the inserting areas of the side plate parts are inserted into the slit holes, the inserting areas of the side plate parts are fixed in a state of opposing the web parts of the steel frame columns, and the bottom plate parts of the connective fittings are fixed in a state of opposing the flange parts of the steel frame girders.