The purpose of this study explain the architectural planning of PICU which is relatively new concept in Japan. There is no suitable development model for PICU. And also, the paper shows the survey result and some recommendations on the issue. A survey was carried out by posting questionnaire survey sheets to 27 children's hospitals and 20 institutes replied, among which 11 replied to have independent PICU. As a results, conclusions are following 1) in a number of PICU's the medical staff is forced to work in very small area and it is recommended that sufficient floor area should be provided as in the some advanced cases, 2) making more comfortable environment for patients and visitors.