Aiming at providing new method and reference for the construction of near-fault design spectra, characteristics of bi-normalized combined spectra of 53 typical near-fault directivity effect ground motions are analyzed by considering the influence of site condition. Results show that the bi-normalized combined spectrum exhibits the highest correlation with the amplitudes of ground motions, and the lowest statistical variability, compared with those of acceleration spectrum, velocity spectrum and displacement spectrum. Finally, site-depended design spectral models for near-fault region are suggested based on features of bi-normalized combined response spectra.