A study was carried out of the Instituto Colombiano Agropecuario-ICA of Palmira between the second semester of 1987 and second of 1989 with the objetive to see of nodulation form and the response of soybean and beans to seven strains of Rizobium of soybean, beans, mungobean, caupi, peanuts, crotalaria and Desmodium. All of especies nodulated after 15 days of emergence also, the nodules lasted in all of especies up to 60 days after emergence except in beans which deteriorated nodules were evident after flowering. The position of nodules were in the main root and secundaries except for beans that only presented nodules in secundary roots; besides, all species presented global shapes nodules except for Crotalaria which showed oval, astragal and baton shape. The size was small in all especies, however, soybean presented big nodules so as 5 mm of diameter. The soybean nodulated specifically with its strain; however, beans presented effective nodulation with other strains suggesting gesting a wide types strains for this legume and permitting more studies about it.