The geothermal resources are a manifestation of energy, and their occurrence is essentially the process of transferring heat from the earth’s interior to the surface. The southeast coast of China mainland shows significant geothermal activity. However, there are no conclusions about the distribution characteristics of the geothermal field, and how the physical properties of the heat transfer medium respond to the distribution of the geothermal field. In this study, the hot water and underground cold water samples from the ConghuaYonghan research area were collected. The hot water in the research area is generally alkaline, low in dissolved oxygen, and shows relatively reducing environment compared to the underground cold water. The characteristics of hot water samples are mainly Na- HCO3 and Ca·NaHCO3, with a reservoir temperature range of 83~146 ℃. This study summarizes that the meteoric water in the surrounding low mountainous area penetrates underground and migrates along the fault to the deep; and continuously receives heat from the deep mantle heat of the earth and from the decay of radioactive elements in granite by heat exchange with surrounding rock. Subsequently, the hot water migrates upward from the intersection of the northwesttrending fault and the northeast- trending main fault as an ascending channel, that are exposed or bored in the form of hot spring or geothermal well respectively. Combining the analysis of regional geological and geophysical background conditions, such as the Moho depth, the igneous rock distribution and the lithosphere structure in the southeast coast of China, we conclude that the NW main stress effect of the Philippine plate played an important role in the formation of the geothermal system. This study provides a framework for the future exploration and evaluation of the geothermal resources in the southeast coastal area of China.