The study was conducted in three areas, Keban, Agin, and Cemisgezek at Keban Dam Lake, between Dec. 2005 – Nov. 2006. A total of 16315 crayfish was caught, and 5374 were randomly selected for analysis. The population ratio of females to males was 0.81/1.00. The average total length and weight of crayfish is 93 mm, respectively. The ratio of carapax length to total length is 0.48. LogW= 1.4534 + 2.9468LogL was the regression equation for length and weight relationships. Correlation was found to be r2=0.8324. Positive allometric growth was observed in males, and nega-tive growth in females. The cheliped was not found in 8.06% of crayfish.