Earthquake disaster of embankment dams will lead to serious results. At present embankment dams located at seismic area are all dynamically analyzed during aseismic design. Credible dynamic parameters of dam materials obtained from indoor tests are the key to the accuracy of dynamical analysis. Shuiniujia Core Embankment Dam is over 100 meters high and its earthquake fortify intensity is nine. Dynamic characteristics of core cohesive soil and damfoundation gravel are studied through the dynamic triaxial tests. And the dynamic modulus

damping ratio and their influencing factors are analyzed. The results show that the method of using one sample to finish the tests of three different confining pressures ?3c and three different consolidation ratios Kc is feasible

and has accuracy and regularity comparing with the method suggested by “Soil Mechanics Laboratory Regulations”. There are many factors affecting dynamic modulus “Ed” and damping ratio “D”

such as dynamic strain level

confining pressure

consolidated stress ratio and porosity ratio

etc.; “Ed” decreases and “D” increases very rapidly with strain level. And “Ed” increases while “D” decreases with confining pressure. Both “Ed” and “D” increases with consolidated stress ratio. Dynamic modulus and damping ratio are different due to different soils. And dynamic modulus of core cohesive soil of Shuiniujia Embankment Dam are high while its damping ratio is much lower; so it is not easy to suffer the dynamic destroy.