Powder injection molding technology is currently applied to the joining processes to produce multi-functional components. In this paper, the strength of the joint of green and sintered samples produced by powder injection molding was evaluated using four-point bending test. The microstructures of the green samples showed that a very good joint was formed by the re-melting of the first injection molded half part followed by a high pressure compacting in the second injection molding. The strength of joined green samples was almost equal to the reference green samples without joining. The microstructures and flexure strength of sintered joined samples, which was more than 90% of base materials, showed that the good joining was maintained after sintering. This high strength sintered joint was an integrative result of powder injection molding and sintering diffusion. The crack observed at the sample surface accounted for the slight drop of the strength.