Abstract: In this study, the age, growth and reproduction of chub (L. cephalus) population, living in Karasu Stream, was determined. Total 404 chub have sampled and investigated between April 2005 and October 2006. The ages, lengths and weights of individuals varied from 1-7 year, 7.3-40.5 cm and 4.8-1002.5 g, respectively. Length-weight relationship and Von Bertalanffy Growth Equations were calculated as W = 0.00844�L3.1558; as Lt = 60.75�(1-e-0.088(t+0.333)) and as Wt = 3588.04�(1-e-0.088(t+0.333))3.1558, respectively. The mean condition factor was defined as 1.297�0.010. It was established that females and males attained sexual maturity when they reached to 13 and 14 cm in length and third age, respectively and spawning was observed between May and July. The male:female ratio was calculated as 1.45:1. In the population, minimum catching size should be applied as IV age, 18 cm fork length and 70 g total weight.