Submucosal type cleft palate is subdivision of the cleft palate. It is very difficult to find submucosal cleft, because when we exam submucosal type cleft palate patients, it seems to be normal. But in fact, there are abnormal union of palatal muscles of submucosal type cleft palate patients. Because of late detection, the treatment - for example, the operation or the speech therapy - for the submucosal type cleft palate patient usually becomes late. Some patients visited our hospital due to speech disorder nevertheless normal intraoral appearance. After precise intraoral examination, we found out submucosal cleft palate. We evaluated the speech before and after surgery of these patients. In this study, we want to find the objective characteristics of submucosal type cleft palate patients, comparing with the normal and the complete cleft palate patients. Experimental groups were 10 submucosal type cleft palate patients and 10 complete cleft palate patients who got the operation in our hospital. And, the controls were 10 normal person. The sentence patterns using in this study were simple 5 vowels. Using CSL program we evaluated the Formant, Bandwidth. We analized the spectral characteristics of speech signals of 3 groups, before and after the operation. In most cases, the formant scores were higher in experimental groups (complete cleft palate group and submucosal type cleft palate group) than controls. There were small differences when speeching /a/, /i/, /e/ between experimental groups and control groups, large differences when speeching /o/, /u/. After surgery the formant scores were decreased in experimental groups (complete cleft palate group and submucosal type cleft palate group). In bandwidth scores, there were no significant differences between experimental groups and controls.