Models such as Bioecology and the System Theory guide the investigation of family and explain how some variables influence the dynamic of this system, including its relation with children development. This study discusses the impact of family variables on child development, specifically, risk and protection factors, covering development performance at school, as well. Finally, four studies are introduced, with emphasis to the following aspects: sibling interaction, social support, age, availability of resources, parent-children interaction, educational and social-economic level, learning and behavior problems, early intervention program, parental educational practices, parental competence, unemployment, domestic violence, violence against children, drug and alcohol abuse. It can be concluded that the identification of family variables which influence children's development can help the understanding of both the family dynamic and the individuals' development process, making it possible to establish interventions which favor adequate child development.