The goal of the research was to give comparative evaluation of the sperm quality of boars from four breeds: Landrace, Yorkshire, Pietrain and Duroc in accordance with the seasons of the year. The research took place within State Enterprise on Raising and Pig Cross Breeding “Moldsiungibrid” in 2013. The results of the comparative evaluation demonstrated that based on ejaculate content, average per year, better results showed the Landrace and Yorkshire breed boars (255.61 and 276.11 ml); lower ejaculate content had Pietrain breed boars - 253.35 ml and Duroc - 214.27 ml. Semen obtained in one ejaculation from Yorkshire breed boar, has the capacity to bred 11 sows, with Landrace and Pietrain - 10 sows and with the Duroc breed boar semen - 8 sows (on dilution 1:4). It was found that, boars sperm production depends on the seasons of the year: the ejaculate content of Landrace breed boars was lower by 14.84 ml in autumn than in winter and summer; in the case of Pietrain breed boars, it varies from 240.65 ml in spring to 265.78 ml in autumn; in the case of Yorkshire breed boars - from 252.62 ml in spring to 303.87ml in summer and Duroc breed from 191.31 ml in winter till 230.13 ml in summer.