This study was conducted to determine the age and growth of Caspian kutum (Rutilus frisii kutum) in Vali Abad River, Mazandaran Province during 2020-2021. In this experiment, 100 fish were caught using a gill net with a mesh size of 5 mm. Kutum age was determined based on the scales. The results showed that the maximum age of males and females of the study area was 5+ and 6+ years, respectively. In males, the fish were 3+ years old (57.14%) and for females, 4+ years old (35.71%) had the highest frequency among age groups. The highest instantaneous growth rate was recorded in both sexes between 2+ and 3+ years, and this parameter has decreased significantly with increasing age. The relationship between total length and weight was calculated for males TL=3.23W-12.95 (R2=0.92, n=50) and for females TL=3.01W-11.61 (R2=0.85, n=50). Based on Powell’s formula, the growth pattern was isometric for both sexes.
