Computed tomography was performed on 104 patients of cleft lip and palate with continuous 2 mm slice scanning. The type of hard palate was classified into 3 groups, as normal, hypoplasia and aplasia, depending on its developmental degree. The shape of alveolus was also grouped into 3 groups as circular, triangular and asymmetric forms for the evaluation of the maxillary development. The hard palate development correlated with the shape of the alveolus, the diameter of maxillary and mandibular bone, and frequency of sinusitis and otitis media. Evaluation of the hard palate by thin slice scanning is useful in presumption of future facial development.