1) Characteristics of Child Mentality and Religion : From the viewpoint of the contemporary developmental psychology, it is reasonable to regard the religious mentality in children as a product of their development. One of the best achievements which show the relationship between religion and the characteristic of child mentality was made by J. Piaget. He thought that the characteristics of child mentality could be explained by the word "Egocentricism." and that the world conception of children could be. said "Animism, "Realism" and "Artificialism." This idea of his gives an influential suggestion on the origin of religion. In the child mentality, there exist religious elements as such. 2) Magic and Divination in the World of Children : Children live in the world of fairy tales, in which there are many magical elements. Children enjoy these since they do not possess the causality as grownup people. They accept the magics and divinations which are fitted to their community, while they create their own magics and divinations. 3) Religious Sentiments : What makes a behavior religious is "la notion de sacre" as E. Durkheim said, or "Das Heilige" using the words of R. Otto. This is almost equal to the meaning of English "awe, " which, however, means strictly the complex of various emotions : that is Wonder, Selfsubjection and Fear, according to W. McDougall's papers. Therefore, until such emotions appear in child mentality, the true religious feeling . does not come out. 4) Child Mental Attitude to the Established Religions : Though many studies were done on this subject, here is a graduation thesis "The Development of Religious Consciousness in School children" by M. Horie of Kobe University, who questioned about such established religious conceptions as God, Spirit, Haven and Hell and so on. And the children between young childhood and school-childhood have general tendency of accepting easily what they are told because they are too ready to imitate and believe.