Primary and secondary growths of main and lateral axes of Eucalyptus gunnii clone 634 young trees as well as some other aspects related to stem bending were studied in a small group of vertically left and inclined young trees and followed for a period of fourteen weeks. Although all the young trees, i.e. inclined and straight ones, did produce tension wood in the form of G-fibres, tilting was proved to be greatly effective in G-layer formation. Three different types of G-fibres were distinguished, with thin G-layer without an S3; with moderate to thick G-layer with an S3 and “faint” G-layer. The results of this experiment suggest that encountering the interior and exterior stresses the eucalypt employs at least three mechanisms: differentiating secondary xylem gelatinous fibres, eccentricity of growth compatible to G-fibres production and gelatinous fibres in phloem on the upper side of the leaned axes.