This study was performed to investigate the effects of heat treatment on the physical properties of two species of wood under different heating conditions including at 180℃ for 12 h and 24h, and at 210℃ for 3h and 6h. Heat treatment tests for Pinus densiflora and Larix kaempferi were performed in order to assess the effects on the properties of dimension, weight, density loss, and water absorption. The results showed heat treatment caused significant changes in physical properties such as the dimension, weight, density loss and amount of water absorption. The dimension, weight and density of wood after heat treatment decreased as the heating temperature and time were increased. The amount of water absorption was lower in heat-treated wood than that in solid wood until 48hours. However, the water absorption of heat-treated wood was higher in heat-treated wood than that in solid wood at 96hours. The amount of water absorption of solid Pinus densiflora was higher than that of solid Larix kaempferi.