The purpose of this study was to explore the health and illness concepts of hospitalized preschoolers. The subjects were 52 hospitalized preschoolers from 3 to 6 grade in one general hospital. Data were collected through semistructured interviews by author. this study was conducted from Mar 2, 2000 to Jun. 30, 2000. Data were coded and categorized by content analysis. The results were as follows : 1. Hospitalized preschoolers's answers about health concepts were coded and then classificated to 7 categories(physical well-being, food, powerfulness, exercise, obedience to authority, cleanliness, sleep.) 2. Hospitalized preschoolers's answers about health behavior to maintenance health were coded and then classificated to 8 categories (food, obedience to authority, treatment, exercise, cleanliness, powerfulness, sleep, psychological stability). 3. Hospitalized preschoolers's answers about prevention of illness were coded and then classificated to 9 categories(food, treatment, obedience to authority, powerfulness, emotional stability, psychological stability, exercise, physical well-being, ability of social adaption). 4. Hospitalized preschoolers's answers about cause of illness were coded and then classificated to 3 categories(illness, trauma, food). 5. Hospitalized preschoolers's answers about treatments of illness were coded and then classificated to 9 categories(treatment, rest, emotional stability, sleep, psychological stability, food, obedience, exercise, powerfulness). 6. The levels of health and illness concepts in this sample were higher than those of the physical causality.