Abstract: Studied contents of alfalfa saponins of Medicago sativa, Medicagofalcata and Caoyuan No.2 in different breeding period. The variance analysis was made by using program of SPSS 11.5 software, and multiple comparison of was carried out with Duncan methods. The results indicated that from regreening stage to early blooming time, the contents of total saponins in plants were ： Medicago sativa〉 Caoyuan No.2 〉 Medicagofalcata. The contents of total saponins in lucerne was noticeably higher than Medicagofalcata （P〈0.01）. At full bloom stage and pod-besring period, the contents of total saponins in Caoyuan No.2 was higher than the other varieties. At the maturation stage, the contents of total saponins in Medicago falcata was higher than the other varieties.The contents of total saponins plants of Medicago sativa and Caoyuan No.2 in pod-besring period were noticeably higher than other growing periods （P〈0.05）. At full bloom stage, the contents of total saponins Medicagofalcata was higher than the other growing periods.