Oil and gas pipelines are vital aspects of infrastructure projects and may span tens or even thousands of kilometers.These spans may involve different soil structures that may become overburdened and thus considerably affect the seismic peak ground acceleration (PGA) and PGA zonation map. In this study,based on the site amplification coefficient,we examine a gas pipeline project in the North China plain. We estimate the fitting functions of the site amplification coefficient (K_S) and PGA of rocks in different soil layer constructions and obtain a PGA zonation map for the adjacent 10 km area.We then compare our results with those given by the 4^th and 5^th seismic ground motion parameter zonation maps of China.The results show that the practical amplification coefficient K_S lies between 1.30 and 1.45 for 10% probability of exceedance in 50 years,and the amplification coefficient K_S lies between 1.15 and 1.30 for 5% probability of exceedance in 50 years.They are both relatively larger than the values suggested by the 4^th and 5^th zonation maps.The PGA zonation map with 10% probability of exceedance in 50 years shows that local regions belonging to 0.15g or 0.20g zones in the 4^th and 5^th zonation maps of China become 0.20g or 0.25g zones,which demonstrates that the amplification coefficient K_S may significantly influence PGA zonation map classifications.