Latin America´s soils are acidic and nitrogen-deficient, for this reason is necessary to explore new alternatives in order to modulate in the development of plants, specially the leguminous plants. The use of bacteria´s potential to induce nodulation and to fix nitrogen in leguminous plants has been studied as an option with potential impact. In our study, we analyzed the diversity of rhizobial isolated of the bean Vigna unguiculata (beans cowpea) cultured in the north of Bolivar department (Colombia). We identified strains able of growing in hostile environment (which have a potential use like bioinoculants). Additionally, we described an approach to taxonomy of these biospecies. We reached the characterization of 52 rhizobial strains (based on their morphologic, requires of culture, metabolic, resistance to metals and antibiotics and authentication characteristics). According with their growing properties, 63.5 % were slow growth strains while the 36.5 % were of rapid growth. The isolates were characterized according to their assimilation carbohydrate´s pattern, finding microorganism as Rhizobium, Bradyrhizobium and Mesorhizobium (12 of which were identified as potential bioinoculants).