There is provided a jaw motion measuring system that can attach a simple detector and can accurately carry out measurement of jaw motion. The jaw motion measuring system includes: an acceleration detector having at least an acceleration sensor that senses accelerations of three-axis directions, a flexible wire whose one end is connected to the acceleration sensor, an output terminal that is connected to another end of the flexible wire and outputs acceleration data of the three-axis directions, and an attachment portion that attaches the acceleration sensor to a chin portion of a lower jaw and a jaw motion measuring device that acquires acceleration data corresponding to jaw motion from the acceleration detector, and carries out correction, with respect to the acquired acceleration data, of errors due to the acceleration sensor, and measures jaw motion expressed by acceleration waveforms.