Abstract: Cement-soil retaining wall (CSRW) was usually designed on the basis of the trial and error method, which was not only complicated, but also difficult to find out the reliable and economic solution. In this paper the optimization design method of CSRW was discussed, and an optimization mathematic model for CSRW was set up, which took the effective width, the embedded depth and the replacement ratio of CSRW as its decision variables. Genetic algorithms (Gas) were introduced to optimize the design of CSRW, and the influence of structure parameters of CSRW on the optimization design was discussed. Two examples were given to verify the presented method. The comparison of computated results show that the reliable and economical design can be obtained by the proposed method.