An experimental study of the lateral shear performance of wooden floor system sheathed with thick sugi plywood using sugi compressed wooden dowels is described. The objective of this investigation are 1) to study the in-plane shear resistance of wooden floor system sheathed with sugi timber dowels, 2) to determine the effects of the number of sugi timber dowels on the performance of wooden floor system. In this study, 3 specimens of wooden floor system were tested. Each of wooden frame floor system consists of 2 horizontal beams. 3 vertical beams, 4 horizontal supporting beams. All beams were made of solid wood of Japanese pine (Sugi). Each specimen consists of 6 floor panels which are nailed to the wood frame floor system by sugi timber dowels. Each specimen use different number of sugi timber dowels on the edge of each floor panels, that is. 3, 4, and 5 sugi timber dowels. From this study, results indicate that the number of sugi timber dowels will significantly affect lateral shear performance of wooden floor system.