The aim of this study was to determine the variability in yield and fiber technological properties in advanced cotton lines developed through cotton breeding program of the Southeastern Anatolia Agricultural Research Institute (SAARI). The experiment was conducted in the SAARI's experimental field according to Augmented Design (AD) with six replications. In the study, 66 advanced cotton breeding lines and 3 control varieties ('Stoneville 468' , 'GW-Teks' , and 'Fantom') were used as plant materials. -1 for fiber yield. It was determined that ginning percentage was more than 39.85% for the 10.14%, fiber length was more than 29.76 mm for the 18.84%, fiber strength was more than 31.78 g tex -1 for the 8.7%, and fiber uniformity was more than 86.55% for the 13.05% of the materials. It was also determined that 1.45% of the material was very thin and 13.04% of the material was above 6.59% for fiber elongation and for short fiber index of 46.38% of the material ranged from 6.90 to 7.63.