Aim. To establish the features of somatometric maturity of premature infants in the sensitive period of development. Material and methods. The somatometric method of the study was used to examine 124 children aged 7 years, who were divided into control and main groups. The control group included boys and girls with a history of traditional gestation periods. Boys and girls of the main group had all the signs of anatomical and physiological prematurity. Somatometric studies were carried out according to the traditional method, which included measurements of the overall dimensions of the body. On the basis of somatometric indicators, the indices of proportionality and harmony of the physique were calculated. The body types of children were determined according to the recommendations of V. G. Nikolaev (2007). To perform calculations of individual components of body weight, the manual of E. G. Martirosov (2010). Results. Somatometric studies have established sexual and intergroup differences in the physique of children aged 7 years. The analysis of the obtained data revealed the following feature: the longitudinal, transverse and girth dimensions in children of the control group are characterized by a significantly high increase by the age of 7. In children of the main group, the value of somatometric indicators is significantly lower, which is reflected in the lower massiveness and strength of the body of children of this group. It can be assumed that somatometric measurements revealed the features of growth processes in the physical development of children of the main and control groups. Somatometric studies can serve as objective criteria for the physical health of children and allow a more differentiated approach to the assessment of growth processes, as well as to predict possible deviations in a timely manner. Our study showed that the component composition of body weight has a significant impact on the formation of somatotypological features that reflect the degree of reactivity and resistance of the body of children at certain stages of development. The magnitude of endomorphy, mesomorphy and ectomorphy is characterized by sexual and intergroup differences that have a significant impact on the body shape and strength of the physique. Conclusion. Somatometric studies of the body of children aged 7 years allowed us to establish the features of growth processes in children of the main and control groups, which represent the norm of a biological reaction aimed at the optimal development of the child’s body. The revealed features in the morphofunctional status of children have established the mechanisms of compensatory and adaptive reactions that contribute to the formation of a certain morphotype. The structural and functional specificity of children is determined, which provides a certain reactivity and resistance of the body at the age of 7 years. Somatometric differences in the physical status of children are an objective criterion for the sanitary and hygienic well-being of the younger generation, and the data obtained allow us to identify deviations in a timely manner and carry out corrective measures.