The auther observed the oral status of the 14 twins clinically, the obtainde results were as follow : 1. In each twins, the color of the teeth, the form of the uper central incisors, the periodontal conditions and the oral hygiene status were resemble each other. 2. In one twin, the dentition and the size of the palatine tonsil were different each other. 3. In two twins, the occlusion and the number of the dental caries were different each other. 4. In four twins, the eruptions of teeth were different each other.