The purpose of the study was to assess the content of lactoferrin and soluble antigen of leukocytes - 2 in breast milk on the 1st and 5th days of the postpartum period with different duration of lactation. We examined 99 women in the early postpartum period with his full-term babies. Children were divided into 3 clinical groups: group 1 - 30 children who were breastfed for 1 month or less; 2 - 29 children with breastfeeding duration 3-4 months; 3 - 40 babies who have been breastfed for 6 months or more. The immunochemical study of milk was carried out by the method of double immunodiffusion in agar using standard test systems. The content of lactoferrin and soluble antigen of leukocytes - 2 in breast milk was associated with the duration of lactation. In women who breastfed for 6 months or more, its content in colostrum and transitional milk is significantly higher than in women with a shorter lactation period. The highest values of soluble antigen of leukocytes - 2 were found in colostrum of women with the shortest lactation. The content of the studied proteins in breast milk varies from 1 to 5 days of the lactation period - the highest concentrations are observed in colostrum. ROC-analysis of the content of lactoferrin in colostrum, transitional milk, as well as the level of soluble antigen of leukocytes - 2 in colostrum of mothers showed a high predictive value of the level of proteins for the development of hypogalactia. Comparative analysis of the content of lactoferrin and soluble antigen of leukocytes - 2 in colostrum and transitional milk of the mother allows, together with clinical criteria, to carry out early prediction of hypogalactia. © 2020 Stavropol State Medical University. All rights reserved.