The research objective was to study reproduc-tive qualities (multiple fetation, quantity of pigs in 30 days, the live mass of pigs in 30 days) sows of lines and families of breed Landras and to determine the effect of mass selection by these signs on pro-spect. According to the goal the research problems included the definition indicators of reproductive qualities of sows depending on the accessory to lines and families; establishing the correlation coef-ficients between the signs of qualities of sows on lines and families; calculating selection indicators of reproductive qualities of sows (selection differential, coefficients of heritability of signs) and carrying out the definition of the effect of selection on prospect. Multiple fetation in sows of the line of Lexus made 10.0 heads, in comparison with the sows of other lines this indicator was 1.2-1.5 heads more (12.0-15.0 %). Similar tendency was noted by the quanti-ty of pigs in 30 days. Essential distinctions in the mass of pigs in 30 days between Mokko's lines and Lexus were 13.7 kg (R ≤ 0.01), Larsa - 8.2 kg (R ≤ 0,05) in positive side of the last. The highest rates multiple fetation in the families: Karina - 9.8; Burga - 9.4; Lampa - 9.2 heads, respectively in them were higher indicators of quantity of pigs and live mass of the nest in 30 days, and in sows of the family of Karina the mass of the nest in 30 days was 7.6 kg more (R ≤ 0.05) in comparison with in-dicators of the family of Melody. Phenotypic corre-lations between multiple fetation sows of lines, families and the quantity of pigs with a live weight of 30 days on herd from 0.94 to 0.51 (R ≤ 0.001) respectively allows conducting effective selection of sows on multiple fetation of pigs. The effect of se-lection at the existing indicators of selection differ-ential, coefficient of heritability, feeding and use of sows in multiple fetation for generation will made 0.088; the mass of the nest in 30 days was 0.510 kg; the quantity of pigs in the nest in 30 days was 0.168 heads.