This study was carried out in three regions, Keban, Agin and Cemisgezek of Keban Dam Lake between Dec. 2005 and Nov. 2006. The total 16315 crayfish were caught and 5374 crayfish which chosen randomly were examined. The female/male ratio of population was determined as 0.81/1.00. The mean total length and body weight of crayfish are 93 mm and 26.6 g respec-tively. It is determined that carapax length/total length ratio is 0.48. The regression equation of length and weight relationships were found as LogW= -1.4534 + 2.9468LogL, and correlation was found as r2=0.8324. It was determined that positive allometric growth in males and nega-tive allometric growth in females occurred. In 8.06% of crayfish, cheliped was not determined.