Abstract: The rhizobial strains 49L, 50M and 51S, as well as 53 from the root nodules of four sesbania specieshave been isolated.They are fast-growing, which produce acid on yeast-mannitol agar and utilize most of carbohydrates as carbon Source.The optimum growth temperature is 25～30℃, grow well at pH 5.5～9.0 andtolerate to 0.5% NaCl.Strain 53 can also grow vigorously at 35℃ and PH 10, tolerate to 1.0% NaCl.Aslow-growing strain 54 from stem nodule of Sesbania rostrata has been isolated.On yeast-mannitol agar, it produces alkali substance.The pH range for its growth is 6～8, optimum is 7.0.It grows well at 25～30℃, tolerates to 1.0% NaCl and utilizes less carbohydrates.When inoculating or cross-inoculating, the host plantsformed nodules with high nitrogenase and hydrogenase activities.