A Case of a supernumerary teeth on the buccal side of upper right and left molar teeth was observed from a 21 years young Korean female. The characteristics were as follows : 1. The site of the occurrence were resemble on the right and left sides. 2. The cusps of the supernumerary tooth on the right side were resemble to the premolar, and the cusp of the left one was added by one more cusp than the normal molar tooth. 3. The supernumerary teeth were smaller than the normal teeth size. 4. The right and left teeth had only one root.