The causes leading to the nonideal characteristic of the chirped fiber Bragg grating (CFBG ) are discussed. The impact of the group delay ripple (GDR), reflectivity ripple (RR) and bandwidth of the CFBG on the 10Gb/s transmission system where non-return-to-zero (NRZ), return-to-zero (RZ) and carrier-suppressed return-to-zero (CSRZ) formats was investigated and the CFBG employed as dispersion compensator was simulated and compared in detail. The analytical result helps to optimize the practical 1500km CFBG-based transmission and the relation between the system performance and the nonideal characteristic of the grating validated the analysis in this paper.