Glued laminated timber is one of the most efficient constructing materials that allow solving complex architectural and constructional patterns, creating efficient, lightweight, versatile and aesthetically expressional constructions. The major disadvantage of glued wood structures is anisotropy that increases sufficiently in process of its production. Anisotropy of natural and glued laminated timber is considered in the article; particularly it is focused on alteration of elasticity modulus in dependence on angle of load application direction on direction of wood grain. Principal mechanics of natural timber failure is considered in the article. Two methods of timber anisotropy description (orthotropic and transversal isotropic) considered for further development