Ground motions recorded in near-fault areas have some specific characteristics that differ substantially from those recorded in far-fault regions. One of the main features of near-fault records is the pulse-like shape caused by forward-directivity effect. This peculiarity may lead to much more severe damage to bridge structures located in near-fault regions. However, both current Chinese and European codes for seismic design of highway bridges nearly have no consideration on near-fault seismic actions. In this study, typical regular highway bridges in China are idealized as single-degree-of-freedom (SDOF) systems. Then, the Makris mathematical model for the pulse-like records is used to perform a parametric analysis on a settled SDOF system. Effect of key parameters, such as the half-pulse number (n), fundamental period (T0), pulse period (Tp) and the peak velocity (Vp) from the mathematical model, on responses of SDOF systems are analyzed. The potential degradation phenomenon which might happen under near-fault earthquake ground motions is also considered by comparing the ductility coefficient spectrum. The results show that all the key parameters had a significant effect on both linear and nonlinear response spectrum and seismic response. The stiffness degradation phenomenon will lead to a larger ductility coefficient and the Vp is the most effective factor for the response under the near-fault mathematical input.