This paper focuses on the joints of failure mode in traditional timber structures. These joints have strong influence on the strength and performance of timber buildings. The purpose of this paper is clarify the strength and failure mode of pegged, mortise and tenon joint. Static shear loading test of the joint was operated. The combination of bending, shear and compressive failure of the peg within the joint was observed through the experiment. The deformation of all the members of each phase is documented in detail. The failure model of the joint was found to be similar to that of the bolt joint for double shear connections.