DSF length,peak power of pump pulse,te mporal pulse width of pump wave and walk-off parameter are important factors,wh ich influence the shape characteristics of converted pulse in all optical wavel ength conversion system based on NOLM switching effect and XPM effect.We investi gate the effects above theoretically and numerically,and the results are instruc tive to the optimization of the parameters in all-optical wavelength conversion system using NOLM. -