The paper presents the results of a study on the variability of parameters of cellular structure in potato tubers – 5 potato cultivars, 5 locations of core sampling on each tuber (near the stolon, side of tuber, tip of tuber, inner core, and outer core). For microscope observation of the cellular structure an optical confocal microscope was used – „CONFOCAL 2002” (TSRLM). Specimens were in natural state, and composite image was used, containing sufficient number of cells for analysis of the parameters of the structure. Distributions of the geometric parameters of the cellular structure were obtained, related to the cell size (for 2D section: surface area, perimeter, Feret diameters ) and to cell shape: Feret diameter ratio, elongation – E (ratio of the difference of maximum and minimum diameter of ellipse inscribed in a cell to the sum of the diameters), and compactness – C (16 A/P2). Comparison was made of the distributions of all the measured parameters of structure for the sampling locations on the tubers. It was found that microstructure is a characteristic feature of each cultivar, and the location on the tuber affects the structure.