We described a 10-year-old female with a mucoepidermoid carcinoma arising in the palate. She had orthodontic treatment, then the doctor discovered a swelling in the right side of the palate in August, 1996. So the doctor removed orthodontic brace, but the swelling was unchanged. Therefore she visited our clinic. At first the lesion was thought to be a benign tumor. Because of a 26×21mm hemispherium pattern, there was painless swelling of the palate. A biopsy was performed, the tissue was thought to be a malignant tumor. With the patient under general anaesthesia, tumorectomy was performed. Pathological diagnosis was a mucoepidermoid carcinoma (moderate type). Later, extraction of 76_??_ and additional ectomy including alveolar bone were done.