A novel fiber optical 3R regenerator based on optical soliton-effect using highly nonlinear fiber is constructed and investigated for the needs of the high rate and long-haul optical communications. The propagation equation of the pulses in the proposed optical 3R regenerator with the control of optical modulator and filter is established. By the use of the variational approach, the evolution of the distorted optical pulses in the regenerator and the functions of reamplification, reshaping,and retiming are investigated. The relation between the construction parameters and the output performance of the regenerator is discussed. The stable operation condition of the regenerator is revealed.