Abstract: The oedometer tests on undisturbed and reconstituted samples of three soft clays obtained from different districts with different sampling methods were conducted, and the compression curves and the coefficients of permeability under different consolidation pressures were gained. The test results show that the coefficients of permeability of the undisturbed samples are much larger than those of the reconstituted samples for the soil structure at the same pressure and the gap of coefficients of permeability will be smaller with the increasing consolidation pressure. The coefficients of permeability of the undisturbed and reconstituted samples are different at the same void ratio although they have the similar rule between the coefficient of permeability and void ratio. It can reasonably be explained by the difference in large pore-size volume between the undisturbed and reconstituted samples, which can be calculated from the pore-size distribution curves obtained from the mercury intrusion porosimetry tests on the Shanghai soft clay. Finally, the reference void ratio e₁₀^*, which is used to simply illustrate the soil fabric, is introduced to deal with the permeability change indices from different soft clays. The unique C_k - e₁₀^* curve with high relation, no matter undisturbed samples or reconstituted samples, shows that the reference void ratio e₁₀^* is a reasonable parameter to illustrate the fabric effect on the permeability characteristic of soft clay.