Two Er~(3+)/Yb~(3+) co-doped fibers with different ion ratio were fabricated through the MCVD and solution doping method.We explored the amplified spontaneous emission(ASE) of Er~(3+)/Yb~(3+) co-doped fiber amplifier(EYDFA) with 980 nm and 1 480 nm pump schemes.The measurement results showed that ASE spectrum was very weak when the pump light wavelength was near 976 nm.The EYDF with low absorption coefficient has higher intensity than that with high absorption coefficient.This unexpected result is caused by Yb~(3+) unsaturable absorption and low energy transfer efficiency when pump wavelength is at 976 nm.But the ASE intensity of EYDFA pumped by 1 480 nm LD is strong,which is about 5 orders of that pumped by 980 nm LD.