The population structure of Aphanius mento in Kirkgoz Spring (37 degrees 06' N; 30 degrees 35' E) was studied, using 654 fish monthly in 2002. This study were observed in the number of individuals of each sex, age, weight and size compositions. In addition, the total length-weight relationship was calculated as well as the Von Bertalanffy growth equation. A study of the food uptake throughout the year has been carried out by examination of the content of the digestive track. Males made up 52.29%, females 47.71% Of the population. The length-weight relationship and Von Bertalanffy growth equation were W=0.0626 L (2.3348), L-t = 23.51 (1 - e (-1.041 (1+2.904))) and W-t = 786.25 (l - e (-0.002 (t+0.200)))(2.3348), respectively. Gammarus sp. and Palaemon sp. are the major food items for A. mento.