Abstarct: Nowadays, the development of ports and the construction of artificial harbors using seabed sediments is widespread. However, due to the nature of the material used and the method of implementation, often have weakness in engineering characteristics, especially bearing capacity and settlement of the soil. To solve many of these problems, this is essential to improve these characteristics in the soil. One of the common soil improvement methods is soil reinforcement methods, which are often costly because of the costs of supply of material and the implementation. The addition of waste materials to the soil is a proper way to reinforce the ground because of its environmental benefits and the ease of adding it during embankment implementation. Moreover, due to the increase in plastics production in recent decades, it was decided to use waste polyethylene terephthalates for soil improvement in this study. After sample preparation, dynamic tests were performed on soil samples (Bandar Anzali sand) in two treated and untreated cases in 2 different relative densities under various vertical loads by the dynamic Simple Shear apparatus. Then the effect of adding this material on dynamic parameters of the soil was investigated. Afterward, by performing the bender element Tests on similar samples, the additive effect on shear wave velocity and maximum shear modulus has been considered. And finally, soil gradation tests performed using sieves on every specimen to investigate the additive effect on aggregate crushing value. baxsed on the experimental results, under the effect of improvement in the most optimal state of the sample, the amount of shear modulus in low strains increased up to 40% and in high strains, up to 30%, the amount of damping ratio in low strains reduced up to 30 % and in high strains, up to 15% and the amount of maximum shear modulus is increased up to 15%.