Abstract: The liquid crystal spatial light modulator(LCSLM) was used to shape the super-Gaussian seed pulse. The simulation results of the shaping, amplification and compression processes, indicate that the spectrum shaped by liquial crystal spatial light modu letar eliminates the nonlinear effect of Nd: glass chirped pulse amplification system, the spectral width of the amplified pulse is as the same as that of the initial one. But the structural parameters of the device show great impact on the signal noise ratio of the compressed pulse. We analyzed the relationship between structural parameters and signal noise ratio and the results are useful for application and optimum design of such device.