Wood-based panels are widely used in the bearing walls and complex beams as the resistant element against shear force. As shear forces such as frequent earthquakes and typhoons work on them during their service life, the strength properties are predicted to reduce. Fatigue behavior of these panels generated by these natural disasters must be considered in determining safe design loads and for predicting service life of the panels. Fatigue tests of wood-based panels (Plywood; PW and Oriented strand board; OSB) were performed under cyclic shear-loading through thickness. A linear relationship between stress level and logarithm of the number of cycles to failure up to 106cycles existed. Shear rigidity kept its initial value at the beginning of cyclic loading and reduced gradually its value toward the fatigue life. A marked increase in the maximum shear strain was observed just before the fatigue life. These fatigue behavior showed differences between PW and OSB just before the fatigue life owing to their elemental constitutions. Prediction of the fatigue life was made based on the cyclic creep of the maximum shear strain.
