To provide an opening periphery reinforcing member capable of reinforcing efficiently a periphery of an opening while taking a stress transmission mechanism into consideration, and capable of simplifying execution, in a reinforced concrete beam with the opening, and a reinforcing structure and a reinforcing method using the same.

The opening periphery reinforcing member 10 formed substantially ring-likely or substantially cylindrically of fiber reinforced mortal or concrete is arranged in a position for forming the opening of a beam, and respective upper and lower opening periphery shearing reinforcements 11 are engaged with upper and lower main reinforcements 21, 22, to be integrated with a concrete base material 26 together with opening both-side shearing reinforcements 23.