This study describes peculiarities of sperm production by anadromous and precocious parr Atlantic salmon. It was possible to obtain 15 sperm samples with total volume of 130 cm3from anadromous males at the peak of the spawning run. Changes in the sperm characteristics with the increase of the sea‐life age and weight of anadromous males are shown. Such changes are also shown throughout the spawning period. The properties of parr spermatazoa were investigated and it is suggested that these spermatozoa are suitable for inseminatio