Abstract: The Monte Carlo method, which can be used to simulate the surface segregation of binary alloys, is discussed. Using our analytic modified EAM potentials, the surface concentrations and concentration depth profiles of Pd-Au binary alloys are studied with Monte Carlo simulation based on the Grand Canonical Ensemble Statistical Rule. Simulation results show that the topmost surface is enriched with Au, and a damped oscillation of Au concentration is found in the whole composition range. The results are in agreement with the available experiment data and other theoretical values.