Alfalfa (Medicago polymorpha) is an annual herbal plant in the pea family Fabaceae, has the highest feeding value as forage for its soft and highly digestible fiber and high protein content fiber up to 24.5%. Therefore, it recommended to cultivate widely and productively as an ideal forage plant. Inoculated with rhizobia, alfalfa (Medicago polymorpha) can formed effective symbiotic system to fix nitrogen, and subsequently produce high plant growth dry weigh. The inoculation effect on alfalfa (Medicago polymorpha) was performed in three different type of soils from Yingjiang county of Yunnan province by using twelve distinct rhizobial strains such as SWF67523, SWF67409, SWF67456, SWF67394, SWF67501, etc. respectively which were isolated from root nodules of Medicago polymorpha,M. sativa and M.lupulina from Yingjiang and other area of Yunnan. The results showed that the rhizobial nodulation rate, plant height, dry weight and total nitrogen content of plant were all increased significantly after harvested in condition that plant were inoculated with rhizobia (P<0.05), the rhizobial nodulation rate are up to 98.41％, 97.78％, 97.50％ and 96.56％ by inoculated with strain SWF67523, SWF67501, SWF67394 and SWF67350, respectively; Contrasting to the control, the plant height increasing 40.2％, 27.3％ and 25.0％ by SWF67523, SWF67409 and SWF67394 respectively; The dry weight per plant was raised up 106.5% by inoculated with SWF67409 and raised 100.1％, 78.3％ and 74.3％ by the other strains SWF67523, SWF67394 and HBU07001 respectively; Besides, the inoculated strains increased the nitrogen content obviously as well, the alfalfa plant have higher nitrogen content by inoculated with strain SWF67409,SWF67523 and SWF67394 than other test strains. Among 12 strains grew in three types of soils revealed by the whole production of the plant inoculation, strain SWF67523,SWF67409 and SWF67394 were more effective than others; Of the three strains, the performance of indigenous strain SWF67523 from its host of alfalfa (Medicago polymorpha) grew in Yinjiang exceeded the other strains estimated by plant growth. From this result, we could concluded that high effective nodulation and nitrogen-fixation rhizobial strains could be screened from indigenous strains associated with its host legume; on the other hand, we also confirmed that there exist a great specificity between rhizobia and plant of alfalfa (Medicago polymorpha). Moreover, we founded that rhizobia strains were interacted with soil. This conclusion was revealed by the fact that the inoculated alfalfa plant grows in high potassium content available soil as Pingyuan townⅡobtained high plant dry weigh than that grow in other two lower potassium content available types soils. In future, the high effective rhizobial strains obtained in this study will be applied in fields for widely cultivating alfalfa (Medicago polymorpha) and will greatly improve agricultural efficiency.