The research covered 60 children aged 3, 199 aged 4, 402 aged 5 years, from randomly selected kindergartens from the province of Warmia and Mazury. Examinations embraced Moire topography and photometric assessment of the posture of the body in the sagittal plain. Conclusions: 1. At the age of 3, body posture is characterized by the trunk considerably bent to the back and if the bend is to the front then to a very slight extent. 2. At the age of 4, body posture is characterized by the trunk bent to the back and if the bend is to the front then to a very slight extent, with approximately equal angle and depth values and different length and height values for chest kyphosis and loin lordosis. 3. At the age of 5, body posture is characterized by the trunk bent to the back and if the bend is to the front then to a very slight extent, with slightly greater angle of loin lordosis than of chest kyphosis, considerably greater height, length and depth of chest kyphosis than of loin lordosis.