Using a resonant column apparatus,experiments were conducted to investigate the dynamic shear modulus and damping ratio characteristics of typical Quaternary sedimentary soils in the offshore area of eastern Jiangsu. the study examined the significant effects of marine and terrestrial depositional environments,as well as geological age,on the dynamic shear modulus ratio and damping ratio of these soils. the results indicate that: (1)the maximum shear modulus G_max of marine soils increases linearly with depth; (2)the influence of marine transgression on the G/G_max-γ and λ-γ curves varies markedly among different soil types in the offshore area,being strong for clay,moderate for silt,and weak for sand; (3)geological age has a pronounced effect on the G/G_max-γ curves of the tested marine silty clay,marine sand,and terrestrial silty clay,whereas its effect on the λ-γ curves is relatively limited. Based on the effects of depositional environment and geological age,average fitting parameters and recommended values for the G/G_max-γ and λ-γ curves of different soil types(silty clay,clay,and sand)were obtained. These results provide reliable dynamic soil parameters for seismic response analysis of engineering sites in the offshore area of eastern Jiangsu,as well as fundamental data for regional seismic risk assessment and earthquake disaster mitigation.