Investigations were carried out to establish the effect of deep freezing, extent of dilution, and site of applying the spermatozoa as well as the functional state of the female genital apparatus of sheep on the forward movement of spermatozoa. It was found that at the insemination of ewes with freshly obtained undiluted semen at the 30th min following insemination there were single live spermatozoa, in the oviducts their number gradually increased up to the fourth hour, reaching several thousand. The highly diluted semen was found to produce an unfavourable effect on the movement of spermatozoa. Following deep freezing spermatozoa manifested a sharp decrease in their movement capacity. Deep cervical application led to an increased number of spermatozoa reaching the oviducts, however, this number was essentially lower than with freshly obtained semen. The movement of spermatozoa depended also on the functional status of the female sexual apparatus. There were considerably more spermatozoa in that of the oviducts on the side of which ovulation took place.