From the amplification equation of solitons propagating in Er3+-doped optical fibers given in reference1，this paper gives the optimal pumping power for the transparent transmission in the case of distributed amplification. It is shown that the theory is in good agreement with experimental results given previously. The investigation on the optimal pumping in which excited-state absoption is considered indicates that the excited-state absoption seriously damp the pump power, but increasing the auantum transition efficiencv of around-state, can weaken the influence of the excited-state absoption.