Abstract: In this study, adaptation performance characters such as biomass per plant, plant height, leaf length, leaf, width, regrowth rate, length of taproot, and crude protein content of 17 alfalfa varieties grown in the southwest area of Hunan province were measures and analyzed by the grey correlative system, to establish varieties assessment models. The alfalfa varieties, including Millennium, Powerplant, and CW680, performed well in the study area, whereas the other varieties had relatively low adaptive productivities. The order of weight index in the grey correlation analysis was: CP>leaf length>leaf width>thick of stem>height length>regrowth rate>length of taproot>fresh/dry>rootstalk diameter>biomass per plant>number lateral root leaf/stem>root weight. These Results offer scientific evidence for introducing and extending alfalfa production in sub-tropical regions of south China.