Using the transfer matrix method,the influence of the grating parameters on the transmission,polarization dependent loss and polarization-mode dispersion are stimulated for the uniform fiber grating and sampled fiber grating with the asymmetric refractive index profiles.For the uniform fiber grating,the results show that the fringe visibility and the period have obvious impact on the polarization dependent loss and polarization-mode dispersion.For the sampled fiber grating,the maximums of the amplitude,polarization dependent loss and polarization-mode dispersion of all the resonance peaks increase with the increasing of the grating length,no matter what the length of the uniform fiber grating segment and the period of the sampled fiber grating are chosen.The birefringence induced by the asymmetric refractive index has stronger impact on the resonance peak close to the central wavelength than that of far away form the central wavelength.