The interaction between femstosecond optical pulses under Raman self-frequency shift effect and the suppression of it are studied by using numerical simulation. The study results show that the existence of Raman effect makes the interaction between fs pulses different from that of conventional ps pulses. In the early stage

the pulses will attract each other

then they will keep the state of repulsion

the pulse spacing will increase along with the increase of the propagation distance

the pulse drift in propagation and the pulse energy exchange will take place

the propagation distance will remarkbly decrease and the communication quality will seriously worsen. The interaction between pulses under Raman effect can be suppressed by the use of synchronous amplitude modulation in combination with nonlinear gain and filter techniques.