This paper reports a development of long-term stiffness reduction control method of timber lattice shear wall due to shrinkage by introducing compressed wooden wedge into the joint. The effectiveness of the developed method based on size recovery property of compressed wooden wedge was revealed by the long-term test. Also material test and joint test confirmed the phenomenon. The shear wall index of developed wall after 1 year showed 0.97 which was smaller than idealistic value of the wall with no gap but sufficiently higher than the realistic value of normal lattice shear wall obtained by the test.
