Abstract: Dynamic properties of intact loess are studied through laboratory dynamic triaxial tests; and variations with water contents are discussed of its dynamic shear strength and seismic subsidence. Test results show that water content has a major influence on the dynamic properties of intact loess. When taking plastic limit as a bound, variation of water content smaller than plastic limit has major influence on dynamic cohesion and seismic subsidence critical stress; while variation of water content greater than plastic limit has very minor influence on them. Little influence has variation of water content on dynamic friction angle. Through regression analysis of seismic subsidence curves, it is showed that seismic subsidence needs to be considered into loess classification.