Variations in tracheid length and morphological features of tracheid tips within a growth ring associated with the development of compression wood were observed in young trees of Larix leptolepis Gord. and Abies firma Sieb. et Zucc. A reduction in tracheid length occurred with the development of compression wood within a growth ring. Such a decrease in tracheid length was considered to have resulted from a conspicuous increase in the frequency of cell divisions. Formation of compression wood was also accompanied by an increase in certain morphological features of the tracheid tips, indicating that the intrusive growth of the tracheid tips did not proceed smoothly in compression wood. A negative correlation between the tracheid length and the occurrence of abnormal tracheid tips was established in a growth ring containing compression wood. Whereas the variance of tracheid length increased with increasing tracheid length in normal wood, no such relationship could be observed in compression wood.