Abstract: In order to study gain characteristics of forward and backward multi-pumped Raman amplifiers,based on the power propagation equations of multi-pumped Raman fiber amplifiers,the pumped power and signal power along the fiber was calculated combining Ronge-Kuta with shoot calculation method. The calculation results showed that in the forward pumped fiber amplifiers,the signal power was amplified at first because of the interaction between the pumped light,then reduced fast after the peak value,and that in the backward pumped fiber amplifiers,the signal power reduced gradually at first,then increased fast at the end of the fiber. The result is an important reference for the design of the Raman fiber amplifiers.