To provide a belt structure for reinforcement capable of introducing prestress without damaging the end of a concrete structure and simply and efficiently applying further larger load than load in a conventional continuous fiber belt system.

The belt structure is formed from two woven fabrics having narrow width, woven into weft double structures by using a high-strength yarn having ≥17 cN/dtex breaking strength as warp and using a yarn composed of a synthetic fiber and having ≥15% breaking elongation as weft. In the belt structure, outside eyes and inside eyes exist at both ends thereof and the outside eye at either one end end and the inside eye at the other end are formed by one woven fabric having narrow width and the inside eye at either one end and the outside eye at the other end are formed at the other woven fabric having narrow width and these two woven fabrics each having narrow width are sewn together in the vicinity of the central part of the structure.