Complexes with the formula Au(X)(L) (X = Br and I; L = PPh3 and IPr) were conveniently prepared by a quite simple procedure using the treatment of Au(Cl)(L) with MeC(O)X and the subsequent evaporation under reduced pressure. The mechanistic study by DFT calculation with M06 functional supported that the reaction proceeded through sigma-bond metathesis, where Cl atom underwent a more roundabout course than Br atom did.