The influence of storage conditions and storage periods on quantitative changes in potato tubers is presented in the storage season 1999/2000–2000/2001. The study used four potato cultivars: Baszta, Rywal, Triada and Ania. The tubers were stored at the temperature 3–4°C and 8–10°C and relative air humidity 90–95% for the period of 3 and 6 months. After every storage periods for the laboratory analyses determined natural losses, tubers infections with diseases and mass of sprouts, after which total losses were calculated. The gathered crop from the experimental field and total losses were counted in directly tones. The studies proved that the experimental factors had essential influence on the size of storage losses of potato.