The Web-based lecture-scene playback system using the digital picture-card show has been studied to improve the educational quality of lectures with computer-aided slide presentations in universities. In this system, fine still images of lecture scenes, containing the lecturer, the blackboard, and the presentation screen, are periodically taken by a commercial digital photo camera, and the lecturer voice is recorded into a digital file by a personal computer during a class. Then, the digital picture-card show to play back the lecture scenes is edited by selecting one image and the voice file section corresponding to one lecture scene that is defined as the time span of teaching one slide page by the lecturer. The picture-card show is delivered to students through the World-Wide Web system on demand. In this paper, we propose the structured learning assistance function for this lecture-scene playback system, so that students can study important technical concepts in the lecture structurally. This function classifies the lecture scenes corresponding to one concept into five structures, and generates the links between them automatically. Through applications to one course for freshmen in our department, we show the effectiveness of our proposal.