As many researchers and policy makers have considered children to be a special group that should be protected rather than the object for companies marketing, discussions regarding undesired effects of advertising on children have gotten comprehensive interest. Among many kinds of ads, TV snack/fast-food advertising especially has been studied frequently in terms of possible negative influence on children due to the direct relationship with childrens health issues, such as child obesity. Even though there have been many studies and media reports dealing with the negative effects of TV snack/fast-food ads on children, the invisible or secondary effects of the ads have not gotten enough attention. This study focuses on one of the important secondary effects of TV snack/fast-food ads, the conflict between children and parents. Some studies have reported that childrens exposure to TV snack/fast-food ads cause them to keep pestering or nagging their parents to buy specific food products. Also, due to rejections from parents who are concerned about their childrens health, a situation of repeated conflicts between parents and their children emerges. This study examines how TV snack/fast-food ads influence the conflict between mothers and their children. In addition to understanding the conflict situation itself, this study also explores the diverse relationships between the conflict and the many environmental factors surrounding children. These environmental factors include the mothers general attitudes toward advertising, mothers employment status, income level, and the presence of siblings. In-depth interviews and surveys with mothers who have at least one child between the ages of seven and twelve are conducted. As the theoretical frame for exploring the relationships between the conflict and diverse environmental factors, the Ecological Theory of Child Development (Brofenbrenner 1979, 2001) is employed. This study will be one of the few studies testing if the Ecological Theory can be applied in advertising research context by examining the possible relationships among the impact of TV snack/fast-food ads on children, conflicts between mothers and children regarding food choices, and diverse environmental factors which potentially influence the conflicts.