Abstract: CrN nano-scale monolayer film and CrAlN/TiAlN nano-scale multilayer with different periods were fabricated by DC magnetron sputtering. Neutron and X-ray reflection measured reflectivity were used to characterize the surface, interface structures and properties of the multilayer, such as film thickness, interfacial roughness and interfacial diffusion and so on. The results show that there is a difference of 3.8%-4.2% for the film thickness of CrN monolayer and CrAlN/TiAlN multilayer between the measured values by neutron reflectometry and pre-designed values. The interfaces between films and substrate are sharp and less diffusion. Moreover, the film thickness of CrAlN/TiAlN multilayer obtained by X-ray reflection is larger than that of neutron reflectometry. For the multilayer with the smaller modulation periods, the interfacial diffusion may cause large errors for X-ray reflection results.