Abstract: Based on direct mode perturbation method, a new approach is developed to analyze one-dimensional consolidation equation of soil layers with variable properties. The new method has at least second-order precision. The eigenvalues and eigenfunctions of the homogeneous soil layers are used to simplify the solution of differential equation of one-dimension consolidation of nonhomogeneous soil layers. As the result, a set of algebraic equations are obtained, and it will be solved for semi-analytic solution of one-dimensional consolidation equation. According to the semi-analytic solution of eigenvalues and eigenfunctions of the nonhomogeneous soil layers, the formulae of excess pore water pressure and settlement are derived, which vary with time. Using the proposed method, there is no restriction on the variation soil layer properties with depth. It can be applied to the layered homogeneous soil, as well as any other soil layers with property varying with depth in any form. The results of numerical examples show that the method is simple, practicable and accurate.