In clinic, simplified mandibular movement measuring devices are used for diagnosis of patients with stomatognathic dysfunction and recording maxillomandibular relation. It is difficult to understand mandibular movement in three dimensions from the path on the three planes, because the path of mandibular movement is in three dimensional space with time, not separately on each plane. The purpose of this study was to develop the three dimensional analyzing system by computer graphics. Mandibular movement was recorded by Mandibular Kinesiograph. The signals were sent to personal computer and the data were processed by the software. The basic specifications of the program were as follows: 1. Data could be observed from various viewpoints. 2. Necessary section of the simultaneous data could be displayed. 3. "C" was used for the software describing language. Following results were obtained: It was possible to analyze the path of mandibular movement in other coordinate axis and understand the path of mandibular movement in three dimensions more accurately.