Mandibular movements in 7 normal dentulous subjects during lateral and protrusive excursions were studied to investigate the effects of the clinical use of articulating paper on mandibular paths. Mandibular movements with or without the intraoral articulating paper (thickness: 35 microns) were detected as the lower incisal point displacement and were recorded three-dimensionally with the Selspot system. The date displayed on the X-Y chart recorder on the selected plane were analyzed quantitatively. 1. The paths of the mandible differed between the outward (from the intercuspal position) and the return (backward to the intercuspal position) movements. In lateral excursions the return path tended to be antero-inferior to the outward path, whereas in protrusive excursions the former tended to be dextro-inferior to the latter. 2. In lateral excursions the return path tended to be less stable than the outward path. In protrusive excursions no significant difference was found between the two paths. 3. In lateral excursions, 21-34% of the movements performed using the articulating paper deviated from the normal paths made without using the paper, and in the case of protrusive excursions, deviation was found in 21-50%. At or near the intercuspal position, the return path showed a greater deviation than the outward path. Near the edge-to-edge position, however, the relationship between these two path was reversed. 4. It is suggested that, when the articulating paper is used, the directions of the movement should be taken into account and sufficient care should be paid in occlusal adjustment because the range of functional movement may be overestimated.