The formation of PtSi ultra-thin films prepared by pulsed laser deposition during pulsed laser annealing has been studied. The growth sequence of the Pt2Si and the PtSi phases that evolved as the result of the diffusion reaction in the bilayers was examined by X-ray photoelectron spectroscopy (XPS) and the structure characteristics of PtSi were investigated by XPS. X-ray diffraction (XRD) and atomic force microscopy (AFM). Superb uniformity of PtSi films and smooth PtSi/Si interfaces were obtained by pulsed laser annealing.