This research aimed at investigating different aspects of friendship in childhood to contribute and to organize a theoretical model in order to the understanding of the friendship as a complex relations system. 40 children (from seven to 10 years old) were interviewed. Results refer to friendship network (including best friend), space and time coordinates, activities and communication with the friends, psychosocial processes (social support, competition, aggression and reconciliation), cognitive and affective processes (perception of the friends and the relationship and emotions and friendship) and the development of a friendship. These aspects have been discussed based on the possibility of their integration in a theoretical model about childhood friendship. It was concluded that wide theoretical models of friendship and interpersonal relationships are necessary to guide research in the area.