Objectives: Establishment of upper and lower arch forms for subjects from pure races in Upper Egypt. Material: 400 adolescent males with full permanent sets and having accepted normal occlusion were selected for this study. Methods: upper & lower models were prepared, scanning and digitization were carried out using tracer version 2.1.39 Nile Delta company soft ware designed for this study. Five independent ratios were calculated for each upper and lower arch in order to characterize the different arch forms. Means clustering method was used for classification of the arch forms. Results: For maxillary arch 3 arch forms were distinguished; wide, pointed and square. The same forms represented the mandibular arch. For maxillary arch; wide and pointed arch forms showed higher percentages than square arch form. In the mandibular arch; wide arch forms showed the highest percentages.