Abstract: In this paper, the definition of seismic settlement is given, and its influencing factors, including dynamic stress, initial consolidation pressure, cyclic number and soil type, are discussed.It is shown by the tests that, under seismic action, the soft soil presents a gradually increasing residual settlement, while the cohesionless soil shows an abrupt settlement. Empirical expressions of seismic settlement in terms of test parameters and physical indices of soil are given, which can be used when no test data are available.