This study was conducted to provide information for evaluating oral function in infants. It was carried out in Seoul, Korea, from June to Aug. 1992. with a sample of 100 normal children ranging from 1 co 5 years of age. Oral function was measured with Straton's 'Evaluation of Oral Function in Feeding'. The average age at which each oral function developed is listed below : lip closure over spoon- I year ; jaw opening, jaw closure, lip closure while swallowing, sips liquids, and swallows liquids without excess loss - 2 years ; chews food, swallows food without excess loss, and swallows food without coughing-3 years ; and tongue control-4 years. From the above results, it may be concluded that tongue control develops after jaw control and lip closure.