Abstract: A solution to calculate the Gibson’s governing equation of one-dimensional consolidation of soft soil is presented, which is developed from an explicit finite difference method by a modified upwind difference form. The relevant program JEFD01 is prepared. The case of the Florida phosphate industry waste ponds in U.S.A., which was predicted together by nine institutes or universities, is taken to verify the liability and the usefulness of the solution. From the further analysis, it has proven that the self-weight of the underconsolidation soft soil cannot be negligible, that is, the value of B cannot be denoted to be zero.