The specific gravity of wood treated with the essential oil penetration was higher than that of untreated wood. However, in case of oven-dried wood the difference of treated and untreated products decreased, compared with air-dried wood. The shrinkage of treated wood showed no consistent trend and the difference was trivial. In addition, similar trend was shown in each direction. Compression strength parallel to grain of treated wood was somewhat higher than that of untreated wood and the difference was trivial. The difference in static bending strength was slight and showed no consistent trend. The stage of check for Pinus koraiensis and Populus tomentiglandulosa and Alnus hirsuta was 2 stage and 3 stage, respectively. Deformation stage with no relation to the essential oil treatment was 1 stage for Pinus koraiensis, 2 stage Populus tomentiglandulosa and 3 stage for Ainus hirsuta, respectively, and there was no difference in essential oil penetration.