Variability of grain yield and some yield components of 17 durum wheat varieties with native and exotic originated was investigated. This research was performed under rainfed conditions in three different environments (Tekirda , Lüleburgaz and Edirne) during two growing years (2001-2002 and 2002-2003). Significant differences among cultivars, locations and production years were determined. The highest variations among characters were found in grain weight/spike, grains/spike, spike length and grain yield. In the first experimental year, there was a high positive significant correlation between grain yield and grain weight/spike, test weight and 1000 grain weight. In the second experimental year, grain yield showed positive and significant correlations with 1000 grain weight, test weight and stem length. The biggest differences among investigated cultivar of durum wheat were found in stem length, grains/spike and 1000 grain weight. Grain yield of examined cultivars depended mainly on 1000 grain weight, test weight, grain weight/spike and agroecological conditions during the growing period. However, location, production year and genotypes were the most important determinant of potential yield of cultivars. 1252, Fuatbey 2000, Epidur, K z ltan95, Ayd n 93 and Alt n 97 were found more suitable cultivars that the others for durum wheat production in Thrace Region.