The interface of soil and structure is often found in projects. Shear test is one of the main methods to study interface behavior. The simple shear test considering the stress and strain of soil can be used to discover the characteristics of interface. The relation between strain of soil and displacement of interface is not concerned. By comparison of static and dynamic simple shear tests of mucky silty clay under different normal stresses and different amplitudes of shear stress

relation curves of displacement of interface and cycle number of shear load versus strain of soil are presented. It is obtained by analysis of test curve that the shear stress is increased rapidly at beginning of static shear test; the rate of stress increase is slower in test; softening not occurred. When shear stress is smaller the shear displacement is mainly in soil sample; after some displacement is reached the interface slide of soil sample and steel plate is obvious. There is similarly linear of displacement of interface and strain of soil in some extent of strain in static tests; there is good linearity of interface and strain of soil in dynamic tests; the gradient of the relation line of displacement of interface and strain of soil in static test is steeper than in dynamic test; and there is narrow range of gradient of linear relation of displacement of interface and strain of soil.