As the important pathogens of potato storage diseases, Fusarium solani, F. reseum, F. oxysporum, and Erwinia carotovora were isolated from rot potato tubers. The cut potato pieces of the three cultivars, Epicure, Irish Cobbler, and Superior were held in moist chambers of $4^{circ},;14^{circ},;24^{circ},;and; 34^{circ}C$ and 7 days and then rated for suberin and periderm development. The cut potato pieces thus treated were inoculated with the four organisms and held at $24^{circ}C$ for 9 days and then rated for decay. As the temperature and period of holding increased, more suberin and periderm were developed with decrease in decay. Although there were differences in pathogenicity of the organisms, varietal reaction and protective barrier development, the effect of temperature and holding period had greater importance for decay prevention. At $4^{circ}C$ within 7 days of holding period the potato pieces developed no protective barrier with severe decay. It is required to avoid placing cut potatoes directly in cold storage of the low temperature. At $34^{circ}C$ the pieces developed abundant protective barriers even though decay occurred in somecases. Practically no decay was found with moderate protective barrier development after 3 days and 5 days at $24^{circ}C;and;14^{circ}C$, respectively. Since the potato pieces decayed occasionally during the holding period when they were held at the higher temperature, the holding at $14^{circ}C$ for longer than 5 days is considered to be feasible for prevention of storage rots.