Abstract：The principle and the main characteristics of ant colony algorithm(ACA)，a new simulating evolutionary algorithm proposed recently for solving hard combinatorial optimization problems，are introduced. For the purpose of applying ACA to the soil mechanical parameters inversion of embankment dam，the search space of parameters to be inversed is discretized and the inversion problem is transformed into a combinatorial optimization problem. And then ACA is modified by replacing tour length and visibility in ACA with objective function value and standard deviation of objective function value，respectively. At last，the modified ACA is implemented to inverse the soil mechanical parameters of an embankment dam. The results of a simple example show that modified ACA can solve the inversion problem efficiently.
