Civil construction work in coastal areas and problems caused by undesirable soils of these areas in some places has made geotechnical studies essential for the identification and improvement of these substrates. One of the important points in the improvement of soils in all construction projects is the choice of the type and amount of material used in the mixing plan with the soil. This choice is usually based on Requirements for a development activity and practical experience. In this study, firstly, experiments were carried out on the seawater sand mix with cement, clay and nanoclay and soil characteristics such as optimum density and humidity, modulus of elasticity, cohesion and internal friction angle were investigated. Then, using plaxis software modeling, the final displacement, strain, and final ultimate stress were compared. The results of the software investigation revealed that the mixing design of the nano-cement and sandy soil is efficient. The total displacement in cement and nanoclay combination with sandy soil decreased from 1.86 to 0.858 mm. Also, the final strain rate decreased from 55.6 to 11.06% in the combination of cement and nanoclay with sandy soil. The increase in final stress was also observed from 111.47 to 130.71 kpa in the combination of nano and cement.