The objective of this study is to observe the value and rate of change of temperature when heat conduction and heat dissipation are in equilibrium. To this end, a test setup for heat conduction in liquids is constructed by varying the concentration ratios of water and sodium chloride salt using the steadystate flat plate method. The experiments are conducted using aqueous sodium chloride saline solutions with mass concentrations of 0%, 4%, 8%, 12%, and 16% to measure the thermal conductivity of the saline solutions with different concentrations. The experimental results show that as the saltwater concentration increases, the thermal conductivity of the solution first increases and then tends to stabilize.