Children with achondroplasia have many predisposing factors for sleep apnea syndrome, yet the type and severity of sleep apnea syndorme in this population has not been characterized. So we report our case with achondroplasia with obstructive sleep apnea syndrome. This children was a 6 year old achondroplastic girl who was admitted to the hospital with chief complaints of sleeping 20 out of 24 hours. She had a problem with somnolence for the past several years, the drowsiness had became worse and she became go to sleep at inappropriate times such as during meals and during activities of interest to her. Nocturnal bed wetting had recurrent through she had been previously completely toilet trained. Physical examination was nonspecific except for achondroplasia and cor pulmonale. The children's past history was that she had undergone with decompressive surgery because of cervicomedullary compression, well recongnized complication of achondroplasia, at neurosugical department and with tonsilletomy and adenoidectomy due to obstructive sleep apnea at otolaryngologic department before. But symptoms were done at our department. The tracheostomy prevent for acute postoperative airway obstruction and the tracheostoma was sealed off at postoperative five day. She had relieved her symptoms by this surgery and sleep apnea was improved. This case illustrate children with facial deformity have many predisposing factors for sleep apnea syndrome, and many of these factors were correctable.