Abstract：Some behaviors of saturated flyash such as pore water pressure，dynamic strength，and dynamic deformation are studied by the dynamic torsional shear test. The pore water pressure gradually rises with the development of axial strain in the process of the dynamic torsional shear test，but it essentially keeps constant or goes up a little in the latter stage. There are some considerable similarity in strength and strain between saturated flyash and saturated loess. The effects of dry density and consolidation pressure on the dynamic characteristics of flyash are also analyzed.
