Based on the nonlinear Schroedinger equation describing pulse propagation in photonic crystal fibers(PCF),we investigate the effect of pulse chirp on supercontinuum generation in the case of anomalous dispersion by numerical simulation and discuss the way to controlling supercontinuum generation by using pulse chirp.It is shown that both the positively and negatively chirped pulses slow down the spectral broadening comparing with the chirp-free pulse,especially in the case of the negative chirp.This phenomenon indicates that the chirped pulse is a great disadvantage for us to broaden the spectrum.Furthermore,there exists an optimum propagation distance for spectral broadening at which the spectrum is widest under certain initial power.If we increase the propagation distance,the spectral width is constant on the whole.Comparing with the chirp-free pulse,the optimum propagation distance of the positively chirped pulse is shortened and that of the negatively chirped pulse is extended.