The psychological and biological aspects that accompanied to the child development in his different age stages are mainly related to his spatial dimensions. This relationship could be translated to his architectural existence. Various sciences about the upbringing and growth of the child have developed, while architecture in that field has not been able to keep pace with this rapid development. Until now, when people look closely outside the buildings that have been created for young children, they just find a form and content of an ordinary architecture. It is differing from child architecture that should be sourcing from the Children world and becoming a part of him, while he explores the world and shapes himself. The problem facing children's hospitals in Egypt needs to an urgent improvement of their interior designs to be suitable for the personality and tendencies of the child and his perception. This greatly enhances the positive role of interior design, which reflects on raising the morale of the child, achieving comfort and stability during his treatment period, and increasing the chances of recovery and improvement. There is still a chance to reach the level of interior design in children's hospitals that is compatible with the human and psychological needs of the child. If the interior design of children's hospitals developed by the psychological and physical needs of the child, it will speed up its recovery and give him the feeling that he cures in a recreational center more than a health center.