The purpose of this study was to investigate the effects of induced nasal obstruction on the craniofacial skeleton of the growing rats. Ninety five Sprague-Dawley rats of four weeks of age were divided into three groups of which the first group got the one naris occluded, the second group was on both nares occluded, and the third served the control. The experimental animals were sacrified 2, 5, 8, 12 weeks after occlusion of nasal airway by means of electrocauterization followed by preparation of dry skulls, measurements, and statistical analyses. The findings were as follows: 1. The body weight increments in two nasal obstruction groups were significantly lower than the control group. 2. The bilaterally occluded group showed the smallest size in the magnitide of craniofacial skeleton, then unilateral occluded group and control group in order. 3. The dimensional difference in craniofacial skeleton between experimental and control groups were the most outstanding at 5 weeks of experiment in length, and 8 weeks of experiment in width. 4. In spite of various significant dimensional differences among the groups, no distinct description upon the interrelation between the oral respiration and its impact on the craniofacial growth could be drawn in the very experimental design.