The tunable compression possibility of femtosecond light pulses using a one-dimensional photonic crystal containing a nonlinear defect layer has been numerically simulated. The nonlinear material utilized as the defect layer in the middle of the structure is assumed to contain Kerr nonlinearity and high nonlinear response with respect to the applied pump field. The compression performance of this structure in transmission mode for different pump intensities has been investigated. The simulation result shows that increasing the pumping power applied to the defect layer causes the compression factor of the structure to increase correspondingly. Moreover, the role of initial chirp rate of the incident pulse on the compression strength of the transmitted pulse has been considered.