This paper reports the use of for assessment of speech by oronasal acoustic measures. Nasal energy during speech is reflected by nasolance value and graph pattern. The degree of velopharyngeal closure and the situation and movement of other speech organs can be demonstrated. The speech of 120 normal children and 60 preoperation cleft palate patients are studied. The scales of normal value and graph pattern are recorded. Comparing with normal speech, the scale of nasolance value and characteristics of graph pattern of cleft palate speech are obviously changed and may be assessed by this apparatus. The treatment and speech therapy plan can be made with the results obtained by this method as the basis.