AbstractEffects of heat treatment on some physical properties of poplar and plane wood specimens were investigated. The main aim was to compare effects of heat on some physical properties of low-density poplar wood and high-density oriental plane wood. Heat treatment was conducted at temperatures of 150 and 200 °C for 3 h in the presence of air at atmospheric pressure. After the heat treatment, the mass loss; oven-dried density; tangential, radial, and volumetric swelling; fiber saturation point; and moisture content were determined. Regression analyses between mass loss and volumetric swelling were performed. The findings were analyzed statistically with ANOVA and the T-test. The results showed that heat treatment at 200 °C influenced the physical properties of both poplar wood and plane tree wood. In addition, the heat treatment had a little greater effect on the swelling and fiber saturation point of poplar wood than it did on the properties of plane wood.