In the present investigation a significant variation of spiral grain with annual ring number as well as with height in stem was observed. It was also observed that the spiral grain may be significantly different in stands with different site conditions and silvicultural treatment. It will however require further research to gain knowledge about to what extent differences in spiral grain in different stands are due to site conditions and to what extent they are due to silvicultural treatment. In addition to site conditions and silvicultural treatment the development of spiral grain may be affected by the genetics of the trees.