Abstract:This study aimed to provide basic materials for new germplasms breeding of alfalfa with high yield and good quality in the irrigation of northwest desert. Through field experiments, hay yield traits, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of Gannong No.3, Gannong No.5, Eureka and their 16 hybrid progeny were investigated and appraised. The variations of nineteen alfalfa germplasms were great in hay yield characters and nutritive qualities. The coefficient of variation of hay yield is the largest, which is 23.80%, while the variation coefficient of ADF is the smallest, which is 6.00%. A single character comparison between different germplasms showed that White 1# had high hay yield, being 22.72 t/hm2 ;Fast-growing 4# had high CP, being 22.74% while the lower NDF and ADF was for White 3#, being37.85% and 31.17% respectively. Based on the single character, White 1# may be used as the high yield material, Fast-growing 4# may be used as the high nitrogen material, White 3# may be used as the low fiber material. Whether the excellent characteristics of these germplasms could inherit stably still need to participate in next transgeneration detection Based on yield and nutrient quality characters, merging the cluster analysis result of four index and combining gray systematic theory, Fast-growing 4# and White 3# are of high yield, high nitrogen and low fiber materials, Fast-growing 12# is of high yield and high nitrogen material, Fast-growing 1# and White 1# are of high yield and middle nitrogen materials, Fast-growing 15# is of high yield and low fiber material, while White 2# is of middle yield and high nitrogen material. The above mentioned materials as high yield and good quality materials can be used to develop new germplasms. The above mentioned germplasms could be used as good alfalfa breeding materials after further transgenerational screening,