To provide a construction structure and construction method of road, capable of attaining reduction in material cost and in labor by a simple structure to significantly reduce the overall construction cost with a reduced work period.

One or more cast-in-place hardened stages which are hardened and integrally connected in a stacked state by cast-in-place are formed on a foundation part continued to a ground-side inclined wall. A road retaining wall includes a plurality of cast-in-place stages which are hardened and integrated, successively stacked, and integrated also vertically to each other by placing a lightweight hardening material to the inside of a connection form including front and rear forms installed in the foundation part and to a gap with the ground-side inclined wall. A front wall placing cavity frame is attached to the front side of the front form of each connection form through an attachment device for detachably attaching the front wall placing cavity frame to thereby form a front wall placed cavity frame which vertically extends through. After a plurality of integrated cast-in-place stages are formed and hardened, concrete is placed in the front wall placing cavity frame to form a vertical integrated placed wall integrated to the plurality of cast-in-place hardened stages.