The clay and sea sand in coastal areas are abundant and appropriate ratio of clay mixed with subsea sand can be used for constructing seawall theoretically.Adopting the DDS-70 cyclic tri-axial test system and GZZ-50 resonant column test system,we carry out the experimental study on the dynamic behavior of the subsea sand-clay mixture with different blending ratios and obtain the dynamic strength and maximum dynamic shear modulus it.Moreover,the influence of the blending ratio and confining pressure on the dynamic strength and maximum dynamic shear modulus are analyzed.The results show that the dynamic strength and maximum dynamic shear modulus increase with the enhancement of the confining pressure;with the decrease of proportion of sand and the increase of proportion of clay,the dynamic strength and maximum dynamic shear modulus decrease.