The orientation relationship and interfaces of PtSn4 and PtSn with the Pt (001) and (111) surfaces have been studied with transmission electron microscopy. Pt was evaporated onto the NaCl (001) and (111) surfaces to form epitaxial Pt thin films and Sn was evaporated onto the Pt films at different temperature to form PtSn4 and PtSn. Pt was evaporated onto the NaCl (001) and (111) surfaces at 350 ¢J to form epitaxial Pt thin films of [001] and [111] zone axes, respectively. Some grains are in random orientation and other as ring pattern. The grain size was at about 10-20 nm. Sn was evaporated onto the Pt surface at 150 ¢J to form PtSn4 and at 200 ¢J to form PtSn. No good orientation relationships were formed on both the PtSn4/ Sn and the PtSn/ Sn interfaces. Heterogeneous nucleation theory, predicts that PtSn should form before PtSn4, but PtSn4 was observed to the first to form. The possible reasons were discussed. Keywords: PtSn4/ Sn interface, PtSn/ Sn interface, orientation relationships, thin films, evaporator, transmission electron microscopy