Abstract: Two-wavelength clock reshaping via four-wave mixing has been studied by simulation. A pump which is shared by the two channels of clock signals is coupled into the highly nonlinear fiber with a probe. Interchannel crosstalk of four-wave mixing can be avoided when we add a time delay into one channel to separate the two clocks. Two idles generated via four-wave mixing are the reshaped clock. The relation between duty cycles of the input clocks and the quality of reshaped clocks has been studied. The relation of the relative amplitude jitters between input clock signal and output clock signal under optimum duty cycles has also been investigated. When the duty cycles increase, the quality of reshaped clocks improves and then deteriorates. At the optimum duty cycle of 0.14, the relative amplitude jitters fall from 13.934 9% and 13.958 6% to 2.03% and 2.12%, which proves the method is feasible.