This article aimed to discuss the relationship between fundamental elements of group structure and the group experiences arising through them. First, the group structure was organized into five categories from an unstructured to structured order as follows: 1) time and space, 2) membership and group size, 3) staff roles, 4) orientation, and 5) settings. Second, the group experiences gained through such group structures were further organized into other five categories, in order from practical to community experiences, as follows: 1) psychological and social benefits, 2) dialogue: self-disclosure and feedback, 3) beliefs and order, 4) family, and 5) gregarious human existence. The discussion of the structures can serve as a reference frame for the speculation of how people, who are gregarious by nature, form groups, and how they form new ones. The discussion of these experiences will provide a perspective for understanding how humans originally tried to be in groups, and the actualization that occurred in these groups.