Ecology of the Metro implies recognition of two interventions; on one hand; contributions in terms of configuring space; management of stations and facilities; on the other; participation of those who transit and through use transform but are also transformed. The user-space interaction emerges as shaper and recipient of environments. Beyond its structures and functioning as part of the city; the Metro operates as a framework of representation; which responds to historic; economic; political and social dimensions. From a situated and interactionist perspective; this paper focuses on these interconnected aspects that result in the performance of the actors; as well as; the performance of the actors as a trigger for these processes. This is part of ethnographic work done in Barcelona‚Äôs Metro; through micro-study it attends to the relationship between social actors and space from which it underlines aspects of mobility; control; interaction and production of environments.