Natural soft clays are generally subjected to the effects of soil structure. So evaluating the influence mechanism of soil structure on the compression behavior of soft clays is of utmost importance. One dimensional consolidation tests are performed on two natural soft undisturbed clays to obtain their compression curves

which are compared with the collected consolidation test data for 39 natural soft clay samples collected in literatures. It is observed that the compression curves under logarithmic coordinates show an inverse S-shape and obvious consolidation yield stress. The oedometer test data can be well represented by two straight lines under bi-logarithmic coordinates and the consolidation yield stress can be easily obtained. Relationships between compression index in the post-yield state and water content at yield point for total 41 clay samples can be well quantitatively presented

which is consistent with the quantitative relationships for remolded clay samples between compression index and corresponding water content at yield point. Comparison results show that the compression behavior of natural clays in the post-yield state is mainly controlled by the water content at yield state

which is independent of the resistance of soil structure. Compression curves for natural clay samples lies above the corresponding curves of remolded samples can be explained as being induced by the difference in water contents.