By letting the pulses pass through an electrooptic intensity modulator twice, a simple method for the amplitude equalization of high repetition rate pulses generated from a p order rational harmonic mode locked fiber ring laser when p<5 was proposed. The modulator was used as both a mode locker and a pulse amplitude equalizer in the cavity. A theoretical explanation based on time domain analysis was used to find appropriate parameters to obtain equalized pulse train and the experimental results agree with the theory.