Steam treatment is often applied to beech (Fagus orientalis Lipsky) to improve the stability and permeability of the wood, obtain a desirable color, and soften the wood. This paper evaluates the effect of steaming on the physical, mechanical, and chemical characteristics of beech steamed for 20,50,70, and 100 hours at 80 degreesC. The results show that steaming decreases the strength and physical properties of the wood. Following 100 hours of steaming, compression strength and modulus of elasticity decreased 13.2 and 16.5 percent, respectively. Steaming had a slight effect on radial and tangential shrinkage, and reduced density about 2 percent. Hemicelluloses in steamed wood decreased only 7 to 9 percent, but wood solubility was greatly decreased. Acetyl content also decreased with steaming as hemicelluloses decreased. The lignin content of steamed wood was slightly higher than that of untreated wood.