Abstract: By introducing a "Disturbed Characteristic Parameter", a method is suggested to analyze effecte of sample disturbance on soil properties in this paper. Based on this method, a mathematical model is presented to describe e-logp curves of test sample with various degrees of disturbance. By using the model, a e-logp curve of a perfect sample can then be computed from the test results of disturbed and remolded samples. Finally, preconsolidation pressure Pc of the test sample can be estimated from the computed e-logp curve. It is shown that the method proposed herein is applicable to most of the clayey soil smaples taken from the four sites and that the estimated Pc values and corrected compression curves may further provide useful data for analyzing other types of soil problems.