Abstract. Domestic sheep breeds potential must be preserved in breeding farms, and the main method of improving the breed is working with breeding lines. The genetic variability of the breed is formed by specialized lines. Therefore, further improvement of the breed itself should be carried out along the way of improving its lines. Each of the lines is specialized according to certain characteristics. The presence of such breeding structures that are not related is one of the ways to improve the productive and biological characteristics of the breed. The method of interlinear crosses in sheep breeding in order to identify optimal combinations is used. The purpose of this work is to study the interlinear crosses of the bright Qigai breed on the basis of retrospective data. Statistical methods were used in the study. Scientific novelty. Tsigai breed young females interlinear crosses in order to improve economically useful traits were analyzed. Results research. The indicators of the live weight of the young females in the interlinear crosses is 53.0 ± 1.1 ... 47.0 ± 1.0 kg with a coefficient of variation of 6.4%. The wool fibers fineness 56th quality in 14.0% of crosses was noted. The interlinear crosses with the 54th quality of wool fibers fineness occupy the largest share by 65.1 %. The remaining crosses was with the 50th quality of wool fibers fineness. The distribution of wool fibers fineness by a positive level of correlation in comparison with the wool length fibers was characterized in the following way: this fact is confirmed by correlation coefficients with a positive level of conjugacy: r = 0.98 ..0.57. The wool fibers fineness in 36.1 % of the obtained interlinear crosses has a strong positive reliable correlation level, and in 47.2 % is weak and unreliable. In the interlinear crosses the wool fibers fineness were noted as follow: 65204 × 1128 in conjunction with the wool shearing, in the crosses 884 × 80077 and 884 × 20832 in conjunction with the live weight of young females.