The amplification of ultrashort optical pulses in EDFA is numerically studied.The results show that when the initial gap between two adjacent optical pulses is small

they will attract each other and produce new subpulses in the course of amplification

resulting in the worsening of the amplification effects.As the enlargement of the initial gap cannot effectively improve the amplification effect

a new method is proposed to introduce appropriate initial chirps into the input pulses

by which the negative effects brought about by the interactions between the optical pulses are reduced and the pulse amplification quality improved.