Abstract: A theoretical investigation with the method of splitstep Fourier was presented on the propagation of a picosecond pulse in photonic crystal fibers.The effect of initial chirp and power on pulse compression was simulated and analyzed.It was found that the compression factor and the compression quality factor increased with initial chirp and power,but optimum fiber length decreased.When the values of initial chirp and power were small,the compression factor and the compression quality factor didn't simultaneously achieve the optimum value.If an appropriate optical fiber length and initial peak power was selected,efficient pulse compression could be attained in photonic crystal fibers.