This work comes from a research that became a systematization and methodological study on morphological physical aspects and the production process of poor settlements which are called in the Venezuelan cities. The barrios are spontaneous settlements, no formally planned, no legal spaces, which have been self-produced by the low income social class of the urban society along decades from the last twenty century till now. The main objective was to offer a methodological proposal for a critical analysis of the intricate physical morphology of the long process of barrio production. This book contents itself a methodology that can be applied to these types of settlements in the cities of the undeveloped countries, since it contains the aspects (social, economic and physical), factors (government, geographical, urban) and variables (public and private spaces) that happen inside them, regardless of their location.