The Present study was conducted to determine some population dynamics parameters of Paracobitis hircanica in Garmabdasht River in Golestan Province during 2011. Sampling was done seasonally using electrofishing (in five stations). The results showed that the male to female sex ratio is1:1.17 which is not significant. The results indicated that the growth rate is greater (or faster) in females than males and also the infinite length of females is greater than males. Both sexes had negative allometric growth model and the condition factor for both sexes was the highest in summer which depends on the better nutritional conditions of this season in comparison with the other seasons