The purpose of this research was to reveal the variability of the morpho-productive characters that determine the development of body conformation, as well as to identify the factors that influence its optimization. The researches were carried out on the batches of lambs from the classic Karakul and Moldavian Karakul races, born in the experimental households: the state farm "Коtоvschii", Dumbrăveni district and the experimental agricultural station "Tevit", Anenii Noi district, Republic of Moldova. The results of the research demonstrated that the body conformation of the Moldavian Karakul lambs is typical of the classic (Asian) Karakul sheep race, with some particularities related to the development of body mass, body length and constitution. Moldavian Karakul lambs are quite full-bodied at birth, with an average body mass of 4.7-5.0 kg, and in some years over 5.0 kg, this being a biological peculiarity of the new type of sheep. Variability of lamb body mass at birth is hereditarily determined (genotypic correlation coefficient rxy = 0.63; h2 = 0.36; repeatability coefficient K0-6 months = 0.26; K0-18 months = 0.23) and influenced environmental conditions, in particular, the nutrition of pregnant ewes. The body mass of the lambs at birth is in a direct-proportional phenotypic relationship with: age of the ewes at calving, body length (rxy = 0.49), skin thickness (rxy = 0.45), fiber length (rxy = 0.22-0.31), furskin surface (rxy = 0.64), loop size and constitution; inversely proportional to: the prolificacy of the ewes in the term and the calving period; curvilinear with: the qualities of own furskin (weight in the flock at calving of the higher class Elita lambs). Lamb body length at birth is in the same similar phenotypic relationships as body mass, including with: skin thickness (rxy = 0.54), fiber length (rxy = 0.15-0.18), furskin area (rxy = 0.78). The constitution of the lamb at birth is in a phenotypic relationship: directly proportional - with its own body mass, body length, thickness and skin reserve; inversely proportional - to skin density.