In this paper, influence of the terminal level lifetime on Nd-glass laser amplifiers has been investigated by using a computer. Results show that, for a Nd-glass laser amplifier with dimension of φ20×480 mm, when the Nd-glass terminal level lifetime is decreased from 100 ns to 1 ns, the influences on an input pulse with a 20 ns width and 2.0 J/cm2 energy density are as follows: the gain increases by～20%; the distortion of the pulse peak decreases by～20%; and the amplifier's saturation length decreases by～30%.