The previous study suggested that the two moderately strong earthquakes that occurred in 1989 and 1991 in the western part of the Yangyuan Basin near the junction of Hebei and Shanxi caused a consequent stress adjustment on the eastern side of the basin implying a new seismic activity cycle in the Yangyuan Basin. The seismic activity on the east side of the basin is mainly concentrated near the northern margin of the basin rupture,where the most active section is from Damanggou to Taijiazhuang,and the latest activity of this rupture zone is of great significance for the analysis of the seismic situation. In this paper,four survey lines were deployed in the middle section of the northern rim of the Yangyuan Basin in Hebei,China,to measure Rn,CO₂ and Hg concentrations in phase 2,and to analyze soil chemical composition in phase 1 in the profiles of Nankou and Taijiazhuang to study the spatial differences of soil gas geochemical characteristics in the middle section of the northern rim of the basin and their relationship with the rupture activity. The results show that the high value of gas concentration points are distributed in the faulted steep canyons and fracture zones,and it is feasible to use fault gas to detect the shallow location of hidden fractures in this area. The intensity of soil gas release in the Nankou section is relatively higher than that in other sections,and this difference in concentration spatial distribution may be due to the different degrees of fracture fragmentation caused by geological structure and fracture activity. The total mercury(THg)content in soil and the gas based on the feature that total organic carbon(TOC)in soil can adsorb Hg elements,and the THg concentration distribution characteristics can reflect the fault activity status over a period of time. Combined with the continuous observation data of fixed precursors around the fracture zone and seismic activity analysis,it is concluded that the current activity level of the fault is relatively weak.