There are many resolution enhancement methods to produce 4K-UHD videos including interpolation and deep learning based Super-Resolution, but lack of details, aliasing and unnatural transition are still inevitable and affect viewer’s immersive experience. Therefore, it is necessary to detect authenticity and native resolution of 4K-UHD videos. In this paper, we propose a new native resolution detection method for 4K-UHD videos. The method is based on extracting feature from the DCT frequency domain and integrating this feature in all frames. Our method can determine authenticity of 4K-UHD videos as well as native resolution, no matter which kind of SR model is applied for upscaling.