Optical signal regeneration including Re-amplification and Re-shaping regenerator has been revealed as the needs in optical communications system particularly in Wavelength Division Multiplexing (WDM) system. Based on this, the idea of modeling the WDM regenerator has been proposed. 2R regenerator based on High Nonlinear Dispersion Imbalanced Loop Mirror (HN-DILM) constructed by Dispersion Shift Fiber (DSF) and Highly Nonlinear Fiber (HNLF) are evaluated and compared by computer simulation. The simulation results show that the HNLF based are preferable for employing in the transmission system owing its sufficiently high signal quality.