As the number of nursery facilities and infants who stay there is continuously increasing, IAQ (Indoor Air Quality) of nursery facilities should be managed strictly and thoroughly because infants are more susceptible to infections due to their low resistivity. In this study the characteristics of IAQ and ventilation associated factors were investigaed for suggesting a desirable condition for IAQ management. Environmental factors were not much related to IAQ characteristics rather than internal factors such as structures of the room. And the positive effect of ventilation on IAQ was obvious and seemed to hinge on factors related to window area especially window/wall ratio. Results of this study indicate that the structure with broader window area of a room and frequnet ventilation can be an effective way for keeping IAQ of nursery facilities clean and safe.