Augmented Reality (AR) is a technique that superimposes virtual content on top of physical objects in the video to provide the viewer with additional information. A welldesigned AR system enables people to acquire information related to the real scene objects easily, which also makes further interactions with the real environment possible. Project-based learning (PBL) has been recognized as an effective approach to trigger learner's motivation, which can further promote their higher order thinking and acquisition of academia knowledge. PBL thus has been commonly used in advanced courses in engineering departments. However, it is quite challenging for engineering students to develop an AR system that is well-functioned and carefully addresses the demands of target users by using conventional PBL approach. The key issue alarms us is that developing a useful and satisfactory AR system requires interdisciplinary knowledge and skills from the areas of both computer science and design. Therefore, an interdisciplinary PBL (IPBL) has been proposed in this study, in which students from the engineering departments and the design departments are strategically grouped to work collaboratively on a medical training AR project. A wide range of evidence will be collected and analysed, which enables this study to investigate the effect of the IPBL course on the students' learning motivation, learning self-efficacy, creativity, and problem-solving skills that are necessary for innovation and excellence in their future career as professional AR application developers.