To sumup, an added amount of Rhizobium taken From soil where yard long bean had been continuously grown for two years to each of the managed test tubes at the initial day produced some large amounts of rhizobialpopulation, whilst the subplots added with nitrogen (control subplots) produced none of rhizobial population and the differences were large and of statistical significance. All managed subplots added with native rhizobial population gave some similar amounts of rhizobialpopulation. At day 30 after planting of both cultivars of yard long bean seedlings, the treated management subplots (native Rhizobium) gave significantly greater amounts of rhizobial population over the control management subplots. The highest amount of rhizobial population was found with the management subplot being used for the growth of KKU25 yard long bean plants while both white seeded managed subplots and the non-managed subplots ranked the second and none was observed with the control subplots. In spite of the amounts of rhizobial population at day 60 after planting decreased with time yet all native Rhizobium added managed subplots had significantly greater amounts of rhizobial population than that of the control subplots. Nodule number were highest with KKU25 cultivar followed by white seeded cultivar and the lowest was found with the non-managed subplots but none of them was found with the control subplots. There were no statistical differences found among the four managed subplots since the control subplot received some amount of nitrogen from chemical fertilizer (70 ppm) from rhizobial fixation hence the amount of yard long bean plant fresh weights were similar in all of the four management subplots.