The microstructure of permafrost ground contains clues to permafrost formation and hence its preconditioning to future change. We applied X-ray computed microtomography (CT) to obtain a high-resolution (Δx = 50 µm) dataset of the composition of a permafrost core drilled in a Yedoma upland in northeastern Siberia. The CT analysis employing image processing allowed to directly map and quantify excess ice, gas inclusions, and two distinct sediment phases. Using laboratory measurements of coarsely-resolved core samples, we statistically estimated the composition of the sediment phases and indirectly quantified pore ice, organic, and mineral contents. We conclude that CT is a promising method for obtaining physical properties of permafrost cores which opens novel research potentials. Technical Remarks: Visualization of permafrost core composition using computer tomographic imaging The frozen permafrost core was taken in 2017 from the Yedoma complex, Kurungnakh Island, Lena River Delta, Siberia. Typically, the permafrost is composed of various proportions of organic and mineral material, pore ice, and excess ice. X-ray tomography and imaging techniques are used to determine the internal structure of the core. The videos show the structure of the frozen material at 70 cm depth below the land surface. The thickness of the depicted fragment is 1.25 cm (250 images with a spatial resolution of 50 µm). 3D models were built with a free image computing platform 3D Slicer. The sample size is 500x500 pixels. The image classification is based on histogram-based manual thresholding segmentation. The imaging-based classification cannot resolve the composition of all the material, only excess ice and air can be clearly distinguished. Thus, when the material is not clearly identifiable due to mixtures of these components (pore ice, organic, and mineral material), we have named them "A" and "B".