The objective of this study was to determine the General Combining Ability (GCA) of parents and the Specific Combining Ability (SCA) o fhybrids. in the breeding program to develop better yielding and high quality cotton varieties under drought stress conditions. Five cotton lines (Blightmaster, Sicala 33, Tamcot CD 3H, Cabu CS 2-1-83 and Kurak 2) and 3 testers (Maraş 92, Erşan 92 and Stoneville 453) were crossed in a line x tester mating design at Southeastern Anatolia Agricultural Research Institute in 2001. Eight genotypes and 15 F1 hybrids were grown in a randomized complete block design with 3 replications at the same experimental area in 2002. From the trial it was found that in the population, seed cotton yield, fiber length, fiber fineness, fiber strength and fiber elongation properties were influenced by additive; lint percentage and 100 seeds weight was influenced by non-additive gene effects. Heterosis values for fineness and fiber elongation were negative, while the other characters were positive. It was observed that Blightmaster for seed cotton yield and fiber elongation, Erşan 92 for lint percentage, Sicala 33 for fiber length and fiber strength were the best parent cultivars and also having best general combining abilities. It was also obvious that Blightmaster x Stoneville 453 for seed cotton yield, Tamcot CD 3H x Erşan 92 for lint percentage, Tamcot CD 3H x Maraş 92 for fiber length, Tamcot CD 3H x Stoneville 453 for fiber fineness, Sicala 33 x Stoneville 453 for fiber strength, Cabu CS 2-1-83 x Maraş 92 for fiber elongation, were the most promising crosses
