Abstract: A new model that accounts for the effects of dispersion on stimulated Raman scattering crosstalk in wavelength division multiplexed systems with random initial binary data is proposed. The formula for calculating the middle distance step is given. According to the model, the output power from each communication channel, which passes through the wavelength division multiplexed fiber system that has dispersion “walk-off” under the random digital sequence modulation and the function of non-linear effects, was numerically calculated. The conclusion that fiber dispersion may reduce the output power fluctuation caused by SRS effect was obtained. The results show that the deviation of output power is significantly reduced in the presence of dispersion. The change of the standard deviation of system output power with the dispersion coefficient under the SRS effect is plotted. The mechanism causing the phenomenon was quantitatively analyzed. The model works with any fiber dispersion, input power and number of channels.