The aim of the paper is to characterise the anterio-posterior spinal curvatures in a chosen development period in girls contrasted with their somatic development. Research hypothesis: the anterio-posterior spinal curvatures are formed along with development, and changes of the values of particular characteristics depend on the age of the examined. Material: the research was carried out in a group of 667 girls, aged from 6 to 16 from Płock who were randomly chosen from kindergartens and schools. Method: the analysis of the spinal curvatures in the sagittal plane was carried out by means of the photogrammetric method, which employs the Moira effect. The following parameters were determined: the total length of the spine, the percentage of the total length of the spine in body height, the length of lumbar lordosis, the percentage of the length of lumbar lordosis in the total length of the spine, the depth of lumbar lordosis, the length of thoracic kyphosis, the percentage of the length of thoracic kyphosis in the total length of the spine, the depth of thoracic kyphosis, the inclination angle of the lumbo-sacral section of the spine, the inclination angle of the thoraco-lumbar section of the spine, the inclination angle of the upper thoracic section of the spine. Conclusions: 1. Spinal curvatures in the sagittal plane are characterised by certain autonomy in relation to somatic development. 2. The total length of the spine shows a tendency toward decreasing of its percentage in body height. 3. The lumbar section of the spine is a curvature which intensively increases its length.