Abstract: Based on the exponential curve fitting method, a new method for calculating the consolidation coefficient-the geometric progression method was put forward.And based on the settlement observation curve of the trial embankment of an express railway on soft clay ground, two kinds of methods were compared and analyzed by calculating the consolidation coefficient.The results showed that the rule of va riation of consolidation coefficient calculated by the geometric progression met hod was clear, and it could avoid the influence of error brought by the exponen tial curve fitting method.The results of the geometric progression method and th e laboratory test belonged to the same order of magnitude.