Synchrotron radiation photoemission spectroscopy (SRPES) and conventional X-ray photoelectron spectroscopy (XPS) were used to study the Fe/ZnO(0001 ) interface formation at room temperature. The interaction extent of Fe overlayer during the ZnO substrate was carefully monitored during the increase of Fe coverage, the results showed obvious Fe2+ formation at the initial stage of Fe deposition. Based on the photoemission spectra (PES) changes observed during the deposition of Fe on ZnO up to 3 nm, three meaningful and critical thicknesses have been observed which may be related to the surface charge transport, chemical reaction, and magnetic property, respectively. The new finding may be helpful to the design of related devices based on Fe/ZnO interface.