This study aims to understand the Process of Communality formation among the Families of Communal Childcare Cooperative. Ethnographic, in-depth interview and participant observation at field are used as method. The families of communal childcare cooperative form their communality through investment and harmony, making relationship, and struggles and overcoming the struggles. Each family is willing to put in their money and time for an unfamiliar group to organize and manage a community. They head for the same direction accepting the diversity of expectation and thought based on the diversity of environment of each family. They have interactions upon the basis of equality among the families. Sharing their unique cloture such as communal place(teojeon), common issues, same generation, unique terms, specific modes of speaking informally or nicknaming, they accept the diversities and head for the sameness to have a harmony. In the reset of forming relationship, these families transfer successfully from the field of I and my family to that of group. They escape from a sense of priority that concerns their own family first and then others. They come to be able to consider the group first. Besides, they come to assimilate themselves to the group by identification with the group. They come to form their identity and sense of membership of the group recognizing power of group they belong in their families and local society. The process of forming community among the families of cooperative has inescapable struggles. Each family becomes a real host of the cooperative in the process of overcoming the struggles and experiences a growth of individual and group in the process of looking for the ways of overcoming the struggles. In the end, the families cooperates and reestablish their community.