Abstract: Alfaking, Fields, Pyramid, Reward, Simplot2000, Norva, Hopeland, Multifoliator, Leafking were introduced from American by Lanzhou Institute of Animal and Veterinary Pharmaceutics Sciences, CAAS. These alfalfa species are new American breeds which will be put into the Asian market in the next few years. After completing district tests in arid and semi-arid areas, we cultivated the varieties in a semi-humid area in 2008. Nine introductions of alfalfa grew normally in the semi-humid area and completed all the reproductive cycle with no problems, including no plant diseases and insect pests. An analysis of reproductive periodicity, nutrition component, speed of growth and stem/leaf ratios, showed the daily growth of Fields was 1.47 cm/d and the stem/leaf ratio was 0.7. The daily growth of Alfaking was 1.39 cm/d, and the thick albumen content was 17.57%. The daily growth of Zhonglan No.1 was 1.22 cm/d, with a thick albumen content of 19.58%. Fields, Alfaking, Multifoliator and Zhonglan No.1 were the best varieties. These nine American alfalfas can be cultivated in arid areas, loess altiplano semi-arid areas, and semi-humid areas. They can also be used in homologous areas in the north of China.