This research was carried out to investigate the biological reproduction of Roach (Rutilus rutilus caspicus) retrieval in the Caspian Sea. Each month the samples were selected from Golestan province from October 2015 to September 2016. In total, 384 Roach were caught to study reproductive production in the study area. In the reproductive stage, 145 specimens have been sexually transmitted. In this research, the maximum fork length and weight of the fish were measured at 27.5 cm and 237 g. The minimum fork length and weight for the Roach were 11.5cm and 28 g. The maximum mean Ovum diameter was at the age of 4 years with a diameter of 1.501 ± 0.1 mm and the minimum Ovum diameter was 2 years old at 0.76 ± 0.15 mm. The GSI sexual health index from the minimum was 0.05 and the maximum point was 0.10 for the female fish, also from the beginning of March and during the month of April we could still see the curve decrease. However, the spawning time began in March and continued until mid-spring. Also, the mean absolute fecundity of the fish was 19469/2 egg. The average maturity of 50% of the female Roach population was 138 mm and the mean age of maturities was 50% The male Roach population was 125 mm. By examining the relationship between length and weight with absolute fecundity, there was a linear relationship between fork length and total weight with absolute fecundity. The results of the absolute fecundity test with length and weight factors were found to be significant in the Pearson test.