One of the key issues in the deformation behavior of soil is the measurement of dynamic shear modulus and damping ratio. In order to fundamentally understand the measurement of dynamic shear modulus and damping ratio，using the resonant column apparatus and the cyclic loading triaxial testing system made by GCTS，the resonant column and cyclic triaxial tests on the variation characteristics of the normalized shear modulus(G/G_max)and damping ratio(λ)with increasing shear strain (γ)were performed. It revealed that the variation trends of G/G_max and λ with increasing γ obtained from resonant column tests were consistent with those obtained through cyclic triaxial tests，and the consistency was independent of the depth and soil type. Moreover，the two test methods can be combined to obtain the G/G_max and λ of soil with a strain range of 10^?6 to 10^?2，which can provide reasonable curves of the G/G_max and λ for nonlinear analysis on seismic site response of major projects.