Barcelona has an important dynamic in its urban structure, with an impact on the environment. For management and planning at municipal level it is necessary to know how the city is structured and how it changes over time. This work presents the Map Barcelona Organic (MEB), which has three editions and collects almost three decades (1977 — (2004) changes in the structure of the city. It depicts the ecological areas that they make up the urban system, i.e. different types of natural and semi-natural areas, and urbanised. Of the third edition, it is worth highlighting its high level of resolution thanks to the basic images are colour orthophotos with a 0.5 m pixel and hierarchical legend it presents, in full detail, 58 categories. The main results of the comparison MEB editions show the urban densification process suffered by Barcelona at coastline of unbuilt crops and solar sites, practically depleting the free soil of the municipality, but also the restoration of the forest, and the significant increase in green areas.