In order to obtain high-strength materials, several plastic deformation processes such as ECAE (equal channel angular extrusion) process is effective. However it is hard to produce a workpiece with elongate workpiece because the dimensions of dies for ECAE process influence the shape of the workpiece. Therefore, one of the best approaches for elongated shape is welding. However, there are few studies concerning about the welding property of deformed materials by ECAE. In this study, the friction welding properties of aluminum alloy deformed by ECAE process were investigated. Two kind of material were used for the friction welding tests. The one was as-received aluminum alloy (A6063-T5), and the other was the alloy deformed by ECAE process. The friction welding tests were carried out by the dedicated welding device modified from a general-purpose lathe. After welding, welding joints were evaluated by the appearance, the mechanical properties and microstructure observations. In the workpieces produced by ECAE process, the same behavior on the friction welding had been observed compared with conventional materials. It was necessary to optimize the welding conditions, in order to minimize the softened zone on welded joints.