Abstract: Four different types of soil were made by mixing Nanjing Xiashu soil and fine sand in different proportions. The resistivity
of soil with different water content was measured by four electrodes method. It was found that the resistivity of soil decreased with the
increase of water content and clay content. Meanwhile, the thermal conductivity of soil samples was tested by DRE thermal conductivity
apparatus, and it was found that the thermal conductivity increased with the increase of water content and sand content. It has been
verified that the soil resistivity and thermal conductivity are related to the physical properties of soil, such as saturation and porosity,
etc. By fitting the resistivity and thermal conductivity of the soil, a good exponential relationship was found. A mathematical model was
established to characterize the correlation between resistivity and thermal conductivity. This study provides the basis for the indirect
determination of the thermal conductivity of the soil by using the measured in-itu resistivity index.