A new scheme of dispersion slope compensator by writing Bragg gratings at different positions in a dispersion compensation fiber is proposed for the wavelength division multiplexing soliton transmission system. This scheme can compensate in-line for the accumulated dispersion of each channel and suppress the dispersive waves which are caused by the incomplete filtering of the signals of the neighboring channels by using Fabry-Perot or Butterworth filters and the different propagating paths of the signals of the different channels in the dispersion slope compensator.