Harris lines have been recognised as an indicator of the stress since the thirties of the last century, when the work of dr. H. A. Harris was published. Despite seventy years of interest, the aetiology of this marker remains unclear. The lines are generally interpreted as being the consequence of a temporary interruption or arrest of bone growth during ontogenesis. Various factors as a trauma, malnutrition and protein deficiency can be the cause of HL's development [e.g. 1]. Clinical studies, have not confirmed these connections unequivocally [e.g. 2, 3]. The lines form in the region of the metaphyses, where the bones grow. Their position vis-a-vis the bone enables to deduce, more or less, the time of their formation [e.g. 4, 5, 6]. The aim of our research was to study the Harris line's formarion in the non-adult population of the Great-Moravian settlement agglomeration at Mikulcice-Valy. We focused only on the non-adult population because it is impossible to rule out the possibility of re-modelling (obliteration) of these lines in adults [e.g. 7]. We recorded the incidence of these markers using X-rays of the long bones of the upper (Hu) and lower (Fe, Ti) extremities. We evaluated a total of 132 individuals. In the first phase, we calculated the intra-observer and inter-observer errors [e.g. 8]. After determining the incidence of these markers on individual bones, we observed the difference in the incidence of markers among individual bones, as well as differences in the distribution of lines in the proximal and distal parts of the bone under study. We also studied the intensity of line formation, which, together with the density of the lines themselves, could indicate the degree of intensity and duration of the stress [e.g. 9]. Finally, we evaluated, the period in the child's life when bone growth was most frequently disrupted [e.g. 6].