A pedal structure for a bicycle includes a pedal body, and an elastic clamping device. The elastic clamping device is mounted on each of the two opposite sides of the pedal body and includes a front binding plate, a rear binding plate, a pivot shaft, at least one torsion spring, an urging plate, and an adjusting bolt. Thus, the cleat can be mounted on and detached from the pedal body easily and conveniently, and can be clamped on the pedal body rigidly and stably by the elastic clamping force of the front binding plate and the rear binding plate.