It is of great importance to study the bandmill tension of the saw blade in improving lumber quality, increasing productive capacity and improving construction of the bandmill.The author has put to tension test the saw blades of bandmills of various constructions Produced recently by the leading woodworking machine plants in the country, and thereby drew proper T-W diagrams. On the basis of the T-W diagrams, safety banding fatigue factors of the saw blades of these bandmills have been calculated. Their average value is 2. 28.On the basis of safety banding fatigue factors and by investigating into the mechanical properties of these saw blades, their tension stress [σT] and tension T have been calculated as follows:According to these two formulas, diagrams of allowable tension stress and allowable tension have been drawn, which can serve as a reference for production and scientific research units.