Disclosed is a syringe cap having a reuse prevention structure, including a reuse prevention cover (50) which fixes a fixed body (20) to the front end of a syringe barrel by fusion or welding, combines a separable body (30) with the fixed body by a screw, and entirely covers the separable body and the fixed body, wherein the reuse prevention cover includes an upper body (51) and a lower body (52). The upper body and the lower body are connected to each other by a connection breakable portion (53), and the connection breakable portion is broken by rotating the upper body in one direction relative to the lower body such that the upper body and the separable body are separated from the lower body and the fixed body, respectively. In addition, the connection breakable portion is easily broken by the twisting of the reuse prevention cover, and by the pushing-up motion of the separable body.
