A wooden truss is a structure comprising one or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes. External forces and reactions to those forces are considered to act only at the nodes and result in forces in the members which are either tensile or compressive forces. Wooden truss structures can be satisfied the request of the diversity and individuality of users, the shortening of the industrialization and the construction cost savings. However, truss has defects of construction-ability. In this study, vierendeel trusses, which is a truss where the members are not triangulated but form rectangular openings, and is a frame with fixed joints that are capable of transferring and resisting bending moments, are suggested and evaluated by experiments. As a result, strengthening vierendeel trusses are show high strengths and stable structure performances.