Abstract: By surveying the damages of termites infesting the dikes at the Qiantang River estuary, it is found that the dikes and dams with saline soil can prevent termite invasion. Based on the findings, experiments are performed for the physical and mechanical indices of anti-seepage earth samples by adding salt and the penetrating ability of termites. The results show that (a) when the soil salinity is less than 2%, the fluctuation of physical and mechanical indices is subtle; (b) when the soil salinity reaches 0.6%, the dikes and dams can effectively prevent termites. According to the dam types and nest-building characteristics of termites, a scientific method of specifying paving locations of saline soil, soil salinity and operating details are developed. The technology is applied to the dams suffering from severe termite infestation, and the effect of termite prevention is remarkable. The technology provides new thinking and method for dam termite prevention.