We propose the high productivity timber joint system based on combining the medium-sized wood lumber as assembly large cross-section member. In general, the wood frame structures are required high ductility performance. In this study, the surfaces of the member joints are covered with fiber reinforced plastics (FRP) to improve the mechanical properties to achieve high ductility wood joints. It will be construction of outstanding architectural space to earthquake resistance by these wood frame structure. The purpose of this study is to investigate the seismic performance of joint and to propose the assembling large cross-section timber joint system by high ductility wood frame structure.