The effect of porosity and saturation degree on thermal conductivity of sands is investigated through laboratory test. The thermal conductivity of four sands is measured using laboratory thermal probe. It is found that thermal conductivity increases with decrease of porosity and increase saturation degree. An empirical equation of thermal conductivity expressed as the function of porosity and saturation degree is developed, its reliability is verified by comparing the predicted results with measured ones as well as results available in the literature.