The article deals with the formation of the social biographies of young people through the interplay of structure and agency. The aim is to provide a grounded typology of patterns of young people's agency within the process of shaping social biographies. The structural context addressed in the article consists of family resources and habitus. The evidence comes from a longitudinal qualitative study with young people from families of workers and families of professionals in two urban neighbourhoods in Belgrade. The narrative analysis of young people's agency that combines longitudinal biographical data and "lifelines" accounts comes from case studies from the last wave of research. Several patterns of young people's agency that have emerged are explored as related to structural opportunities/constraints, and family habitus. It is argued that family resources and support are mechanisms by which social inequality in Serbian society is reproduced during transition to adulthood. On the other hand, young people as strategic actors develop and exhibit different types of agency within the structural contexts of family resources and habitus. (Contains 8 notes.)