The traditional geochemical exploration technique, which uses mainly trace element methods for geothermal systems and can delineate geothermal anomaly areas and search for concealed fault structures, is applied much more to the prospecting in geothermal systems of uplifting mountain type than that in geothermal systems of sedimentary basin type. The conditions of geothermal systems of sedimentary basin type, such as depth of hot water and good preservation which restricts the diffusion of the inorganic elements in geothermal water towards surface, lead to poor prediction effectiveness of geochemical exploration technique. In view of the fact that hot water in geothermal systems of sedimentary basin type is rich in the associated gas such as methane and carbon dioxide, and hence these gases are easy to micro-seep to surface and can be detected because of their strong penetrating power, the authors applied the soil gas method to the field trial to study the responding relationship between surface geochemical characteristics and the geothermal water enrichment area in the geothermal system of sedimentary basin type in Xiongxian County, Hebei Province.The results show that methane and hydrogen in soil gas are effective indicators to delineate the most favorable enrichment area in the geothermal systems of Xiongxian County, thus providing geochemical basis for geothermal systems exploration of similar types.