Abstract: A snoring prevention device is provided to be mounted in the mouth to prevent snoring during sleep, to reduce a volume of the device, and to improve a wearing feeling. The snoring prevention device includes an upper jaw mounting frame having an upper tooth insertion groove into which the upper teeth are inserted, and configured to be mounted on the upper jaw, a lower jaw mounting frame having a lower tooth insertion groove into which the lower teeth are inserted, and configured to be mounted on the lower jaw, and a lower jaw advance unit including a push rod provided at the upper jaw mounting frame at a portion of a center of the upper jaw corresponding to the front tooth side such that the lower jaw is advanced by pushing the lower jaw mounting frame forward when the upper jaw and the lower jaw are closed.