Potato ( Solanum tuberosum L.) belongs to solanaceae , is one of the most important sources of human food. It ranks fifth in world production after wheat, rice, maize and barley and has become an important vegetable crop in Iran, recently. Among the potato diseases, Fusarium dry rot is the most destructive disorder in storage which causes 10-20% crop losses nationwide including Isfahan. Therefore, obtaining appropriate information about the most common Fusarium species causing potato dry rot, mode of its pathogenisity in storage conditions and the possibility of disease control using fungicides are required for efficient disease management. The main objectives of this study were to identify the species of Fusarium sp. currently cause potato dry rot in Isfahan, determination the appropriate conditions for development of the disease and find a way to control the dry rot progress during potato storage. The potato tubers showing Fusarium dry rot symptoms were collected from different suppliers in Isfahan and cultured on Potato Dextrose Agar (PDA). In total, 61 Fusarium isolates were obtained from the symptomatic tubers examined. Based on morphological characteristics, 30 isolates were identified as F.solani, 18 as F.oxysporum , 8 as F.chlamydosporum and 3 as F.semitectum , of which F.solani was the most common species in Isfahan. PCR reactions were performed to validate speciation of the candidate isolates. Molecular identification of F. solani and F.oxysporum was confirmed using specific primer pairs S3R/S3F (491 bp) and Clox2-R/Clox1-F (534 bp), respectively. The universal primers, ITS4/ITS5, were used to amplify rDNA internal transcribed spacers (ITS) regions for detection of F.chlamydosporum and F.semitectum . Mixed infection of F. solani and F.oxysporum was also confirmed using Duplex-PCR method in some infected tubers. The pathogenicity tests of the isolates on wounded tubers showed a great similarity among the symptoms induced by the Fusarium species. Both dry rot and soft rot symptoms were produced in the inoculated tubers by F.solani , Fusarium oxysporum and F. semitectum; although, F.chlamydosporum caused solely dry rot. The degree of rot development in potato cultivars inoculated with the Fusarium species was various in different temperatures conditions. Among the Fusarium species tested, F.solani was evaluated as the most aggressive species, while F.chlamydosporum had low potential to develop tuber rot. According to the results, varieties Marfona and Agria were the most sensitive and tolerant cultivars against Fusarium species, respectively. All four Fusarium species were sensitive to fungicides namely Carbendazim and Benomyl. The fungicide sensitivity tests demonstrated that Carbendazim was the most effective fungicide against F.solani and F.oxysporum , while Benomyl was more efficient to control F.chlamydosporum and F.semitectum growth. The results of this study showed that occurrence of potato dry rot has a direct relevance with storage temperature, the fungal species and the variety of potato. Presence of wound on tuber surface also plays an important role in infection. Considering these results, it seems that use of low temperature in warehouse, tolerant cultivars such as Agria and pre-treatment of tubers with mixture of Benomyl and Carbendazim , can be an effective strategy to decrease Fusarium dry rot losses of stored potatoes. Key words: Potato, Fusarium dry rot, Primers, Fungicide