The author evaluated the effect of wunderer activator for correction of functional enterior corss-bite. The Data were obtained from super-imposition of pre. and post -treatment lateral cephalo-grams. The results were as follows. 1. Correction of anterior crossbite and improvement of facial profile were occurred. 2. Axial inclination of maxillary and mandibular anterior teeth were improved. 3. Slightly down and backwakd rotation of mandible was occurred by the increment of Y-axis angle, anterior facial height and SN-MP angle.