The experiment was carried out with 22 cultivars in the years 1998-1999. The mature tubers were harvested in October and stored at 4°C and 10°C in store-house. Content of reducing sugar was determined after harvest, for 3 and 7 months of storage. Tubers stored at 4°C were reconditioned at 18°C for 2 weeks. It was found that cold storage results cold-induced sweetening. The sugar content in tubers storaged at 4°C increased several times in relation to their level at harvest time (tab. 1 and 2). During potato reconditioning diminishing of the sugar content was twice or threefold depending on cultivar – (fig. 1). Sugar content in tubers after 3 months of storage at 4°C followed by reconditioning was higher in majority varieties than in tubers stored at 10°C (without varieties Panda and Vistula). After 7 months of storage all varieties (without Dessiree, Saturna, Agria) had smaller differences. This study showed that the best processing quality of potato tubers was obtained by storing them at relatively high temperature (10°C) for short periods. However, tubers stored for prolonged periods should be kept at low temperature (about 4°C) and reconditioned before being used.