Maturity age, spawning period, fecundity and gonad histology of the Kura Barbel in Bibi-Sayyedan River of Semirom (Tigris basin) were determined. A total of 445 specimens were captured by monthly collections from August 2010 to July 2011. Specimens were caught by electrofishing, seine net and cast net and transported to the laboratory on ice for further examination. The sex ratio was determined as 1.8M:1F, a ratio significantly different from the expected ratio. Males and females become sexually mature in their first year. Gonadosomatic Index (GSI) value was the highest in April for both sexes. Mean ± SE of absolute fecundity was 8249 ± 997 eggs and also, the relative fecundity was 140 egg/g body weight. Based on the results of GSI, egg diameter and histological studies, spawning period of this fish occur from late March to August with a peak in April.
