Abstract: Potato plants belonging to cv. Morfona were found infected with Potato leaf roll virus (PLRV), Potato virus Y (PVY) and Potato virus S (PVS) with the rates of 3.40, 6.47 and 5.30% in field conditions during the 2003 season. In order to determine the variations in the incidence rates of those potato viruses, harvested tubers from this field used for seed potato for the following seasons for the years of 2004 and 2005. Infection rates for 2004 and 2005 were determined as 7.66 and 22.33% for PLRV; 27.0 and 91.0% for PVY; 21.0 and 77.33% for PVS, respectively. While infection rates of those viruses were relatively low until 2003, the number of infected plants increased in following years. The results obtained from this study revealed that spreading rates of PVY and PVS were higher than PLRV as PVY higher than PVS. Winged aphid counts in the yellow-pan traps during the potato-growing seasons of 2004 and 2005 indicated that Myzus (Nectarosiphon) persicae (Sulzer, 1776), Therioaphis trifolii (Monell, 1882) and Aphis fabae (Scopoli, 1763) were the most abundant aphid species in Central District of Erzurum Province where field trails were established. Nevertheless there was not significant fluctuation of those aphid populations between 2004 and 2005. In addition to those aphids, Anoecia corni (Fabricius, Brachycaudus (Acaudus) cardui (Linnaeus), Cryptomyzus ribis (Linnaeus), Eulachnus rileyi (Williams, 1911), Hyperomyzus lactucae (Linnaeus, 1758) and Pterochloroides persicae (Cholodkovsky) species were collected from the pans but their number were very low.