A nanofilm rotation method is developed to study the rotation of nanograins and the formation of various low energy interfaces. Epitaxial NiO and Ag nanofilms are prepared by ion beam sputtering onto the (100), (110), (111) and (112) surfaces of NaCl single crystal. By overlapping of the above films with an angle difference, and annealing at relatively low temperatures the nanograins are induced to rotate till a stable interface is reached. The rotation process and the stable interfaces are determined by transmission electron microscopy. Many new interfaces between mixed planes are found, and their orientation relationships and structures are analyzed. The rotation speed increase with temperature and is fast above 200oC.