Abstract: With the help of the dynamic consolidation instrument, the shear strength characteristics of loess have been studied. The experiment results revealed that the shear strength varies in stages with increasing number of blow counts (N). During the initial stage, a uniform increase in soil strength is obtained. Upon reaching a limit, the shear strength decreases. A microstructural analysis demonstrates that this variation of shear strength is basically controlled by the alteration of microstructure state in terms of the growing heterogeneity of size and orientation of grains as well as increase in structural damage.