Abstract: Taking the transmission effect of Gaussian pulse with initial chirp passing through a single-mode fiber as an example,the respective relations between linear initial chirp and first-order and high-order dispersion function of single-mode fiber are discussed systematically by means of theoretical analysis and numerical calculation.The sphere and conditions of applying initial chirp to dispersion compensation are pointed out.In a second order dispersion and third order dispersion compensation optical fiber links system,40Gbit/s Gaussian pulse transmission is simulated.It is concluded that as the second order dispersion compensation can avoid pulse broadening,the third order dispersion compensation can not only avoid pulse broadening but also eliminate pulse edges oscillating and temporal shift of pulse peak.