For the evaluation of speech disorders of patients with cleft lip and palate objective, validated and simple evaluation methods are missing. In the clinical everyday life speech disorders are usually assessed by a subjective, auditive evaluation. This is only conditionally suitable for the clinical and scientific use. The automatic speech analysis, as used for automatic speech recognition systems, has already proved being a correct objective method of the global evaluation, i.e. for the quantification of the intelligibility. This could be transferred to the speech of children with cleft lip and palate. In this project a method for the automatic classification and quantification of different typical speech disorders is developed and validated. Such phenomena tension which occur in speech of children and adolescents with cleft lip and palate are hypernasality, a shift in localization of the articulation and changed articulatory tension. With such a method the influence on the intelligibility of these effect can be determined. Furthermore the quality of different therapeutic concepts can be measured.