In 2016, the author monitored the population of Siberian grayling in the Tom’ river and its large tributaries within the Kemerovo region. The aim of the research was to determine the biological parameters of the Siberian grayling population. Observations were conducted from April to October in the Novokuznetsk area. Fishing was carried out by multicellular shutters networks and spinning. The graylings’ length and body weight were measured. The age of the fish was assessed by its scales. The author determined the period of spawning run into mountain rivers and calculated the absolute and individual fecundity of the grayling females. Absolute fertility was determined by the countable-weight method. Individual relative fertility was calculated according to the mass of gonads, the size of the sample and the number of caviars. The article presents data on the development of caviars and the growth of larvae, as well as nutrition and filling of the gastrointestinal tract. The article also includes some oobserved data on amateur grayling fishing.