Wood as a material, types of wood species, wood properties and their distinguishing attributes are discussed. Measurements and evaluation of various physical and mechanical properties of wood as well as wood working quality parameters as per standard procedures are elaborated. The computation of suitability indices and safe working stresses of timbers, interaction of wood with environment and its behaviour and variability in wood quality are presented. A concise list of some important timber species of the country along with their specific gravity, characteristic features and general usage has also been listed at the end of the chapter.