During last decades a voluminous interdisciplinary literature has shown reduction of children’s spatial and social autonomy as well as the privatisation of their extra-curricular activities. All observations show that children’s well-being and development are in jeopardy. As much in Psychology as in Sociology and Geography, this development has been very often explained from a physical perspective focusing on unsuitable spaces. However, the restricted mobility and uses of public spaces also reflect changes in parents’ views of the city. In addition, children’s well-being must also be observed from the change of urban ways of life. In this perspective, we propose in this communication to explore the evolution of the place of safety and security in the children-environment relationships, moreover in the family-environment relationships. We will focus on several perspectives exploring different “sources” of data collected with children and parents in different kinds of urban environments. The first serial of data was collected with children (mean-age= 11y-o) and their parents living in two kinds of urban environments: the centre of Paris and A suburb of Paris. Those data will show the impact of safety on parental strategies for their children and their paradoxical positions. Secondly, we intend to explore urban values and place-identity in order to understand the place of children’s well-being and the importance of safety in it in a serial of data collected with a group of urban citizens (male and female, parents vs non parents) living in Paris and in other French country towns. They answered a questionnaire about the “ideal-city”, a well-known associated-city and their best souvenirs of place during their childhood. Finally, a last collection of data based on comparisons of two groups of families (involved versus no involved in Walking-Bus (W-B) living in Rennes (France) will permit to expose new trends in children mobility. Those results will permit to discuss the contemporary dilemma about children’s wellbeing in urban environment and the question of social diversity. Finally, how children’s mobility affects parent’s relationships to environment Those three sources of data will allow us to understand how safety penetrates children’s uses as well as in children’s well-being. We will see how safety is part of urban values and causes such critical dilemma that it may affect children’s development and in somehow their well-being.