In this study, in order to obtain new findings concerning the occurrence mechanism of dry crack in wood, we investigated the effects of drying temperature and drying rate on occurring behaviors of microcracks during wood drying with using tangential wood samples thin in the longitudinal direction. The development of microcracks occurring in the early stage of drying, furthermore, the possibility of preventing cracks remaining after drying was shown by the obtained results. By controlling the drying temperature and drying rate and thus the state of microstructures in amorphous regions of wood cell wall, it would be possible to prevent the development of microcracks that occurs at the beginning of the drying and the cracking that remains after the drying. And, in order to control the cracks remaining after drying for the actual size wood, it is necessary to clarify not only the mechanism of occurrence for microcracks in the early stage of drying but also the mechanism of the progress of microcracks. The importance became clear in this study.
