Great practical interest has the evaluation of biological efficiency of cows of different exterior and constitutional types and biological value of milk received from them. Because of biological value of milk determined not by individual compo-nents, and the whole composition of substances, as measured by the dry matter content in milk. According to O.V. Gorelik the coefficient, biologi-cal value and biological effectiveness in the eval-uation of cows allows to identify the best animals that give more whole milk. Authors carried out the analysis of change of qualitative and quantitative indices of milk depending on the month of lacta- tion and exterior -constitutional type of cows of red and motley breed of the dairy cattle. The re-sults of the received researches allow determining the efficiency of using of animals of different types of the constitution in the conditions of Krasno-yarsk Region. The aim of the research was to study changes in the qualitative and quantitative parameters of milk depending on the month of lactation and exterior-constitutional type cows of red-motley breed of dairy cattle. The experiments were carried out in 2014-2015 with the use of zootechnical and laboratory methods in east natu-ral economic zone of Krasnoyarsk Region, JSC “Pedigree Farm “Krasny Mayak”. The results of the experiment showed that significant differences in the mass fraction of fat, total protein, casein, whey proteins, minerals, SNF and dry matter be-tween the groups was not established. However, the number of these ingredients due to the higher milk yield was observed, significant superiority of cows tight leptosoma types in the number of lac-tose was 4.4-19 %, SNF was 4.3-19.6 %, dry matter - by 4.3-19.3 %, (P < 0.05-0.001). Biolog-ical efficiency and usefulness showed significant advantage of gentle cow dry leptosomic physique. The difference with mates was according to BACK 1.6-16.3 % (P < 0.05-0.001), BOD - 1.1-11.2 % (the difference is not significant with dense leptosomus type).