To provide an end structure of a partial reinforcing girder of a deck embodied in a simple structure at a low cost capable of preventing local stress concentration even if reinforcing girders having different depths are attached to the part of the deck to be reinforced partially.

A locally loaded part of a deck 1 reinforced with rib members 2 is to be reinforced with additional reinforcing girders 11, in which a supporting member is no more used on the back of a structural member 3 where the end 11a of each reinforcing girder 11 on the basis of the result from detailed analysis. This allows avoiding draw-down of the rib members 2 owing to influence upon the eccentricity originating from different depth between the rib members 2 and reinforcing girders 11, and it is possible to avoid damage when an axially directed stress is applied.