The anaerobic digestion process for the urban solid waste organic fraction (USWOF) by one phases had showed good results for removing of the biodegradable total carbon for a substrate of the USWOF. The recent researches had also showed that anaerobic digestion in two phases favors the global performance of the process, obtaining itself a greater methane percentage in the biogas and a more stable biosolid if it is compared with a process in one phase. However, one of the factors more influence in the anaerobic treatment in one and two phases is the development of the enzymatic hydrolysis, being this first stage of the process in which the degradation of the USWOF is obtained until organic acids, alcohol, amino acids and carbohydrates. [5] The anaerobic digestion will be analyzed in a two phases system and the most relevant parameters to study are: the time of hydraulic retention (THR), the temperature, the formation, the characterization and the evaluation of microbiota in the anaerobic biofilm, the characterization of microbiota responsible for hydrolysis, the evaluation of the hydrolysis index of the cellulose fraction, in addition of the design and