The samples of lean tissue of 6 and 8 months old lambs of various breeds have been chosen as data for meat nutrition value study. We have found out that meat of purebred and crossbred sheep (both 6 and 8 month old) has high biological value. However, it should be noted that lamb meat of animals from the first group (Bakur pure breed (B) and Bakur-Edilbaev crossbreed (BxE)) contains slightly more proteins than lamb meat of animals from the second group (Stavropol pure breed (S) and Stavropol-Edilbaev crossbreed (SxE)), and that meat of crossbreeds of both studied group also contains more proteins that meat of purebred animals. We have not found any significant impact of breed and age of animals on content of most amino acids excluding lysine as lamb meat of animals from S and SxE group contains more lysine compared to meat of animals from B and BxE group (both 6 and 8 months old). According to test results, 100 g of lamb meat produced from 6 months old animals of group B provides 18.3 – 33.6 % of the required amounts of essential amino acids, lamb meat produced from the similar animals of group BxE provides 20.3 – 35.8%; group S – 13.6 – 48.3%; group SxE – 14.2 – 50.3%. We also found out that limiting amino acids of the protein of lamb meat from two studied animal groups (B and BxE; both 6 and 8 months old) are valine, phenylalanine and tyrosine. We have not found any limiting amino acids in the protein of lamb meat of animals from groups S and SxE (both 6 and 8 months old). Amino balance/imbalance coefficient indicates that amino acid content of lamb meat protein for all studied animal breeds (B, BxE, S and SxE) and ages (6 and 8 months old) is rather balanced compared to ideal reference protein.