To provide a concrete structure and a joining method of a concrete structure, which enables a plurality of precast concrete members to be easily connected to one another.

Two precast panels 3 constituting the concrete structure 1 have a concavity 9 on the top surface 7, and a sheath conduit 15 is horizontally provided between the vertical surface 8 of the concavity 9 and the side 4 of the precast panel 3. In order to construct the concrete structure 1, first, the precast panel 3a is arranged in a predetermined position. A PC steel bar 11 is inserted to the sheath conduit 15 provided in the precast panel 3a, and a nut 13 is provided to the end of the PC steel bar 11 positioned in the concavity 9. Then the precast panel 3b is arranged while the PC steel bar 11 projected from the precast panel 3a is inserted to the sheath conduit 15. After the precast panel 3b has been arranged, the nut 13 is provided to the end of the PC steel bar 11 which is positioned in the concavity 9 of the precast panel 3b, and the PC steel bar 11 is fixed to the precast panel 3.