Alfalfa is a productive and excellent legume forage extensively planted in North China and successful hay curing technology is important to the alfalfa industry.In this article,the effects of cut period,sunning hours,baling time,and tedding on the second cutting alfalfa hay were studied with three-year-old alfalfa in 2004 in Hexi Corridor area of China in order to determine the appropriate curing technology of alfalfa hay.The results show that the key factors for the successful alfalfa hay curing were sunning hours,tedding time,and baling time;harvesting period and baling time had great effects on alfalfa hay quality.According to the experiment,higher quality and nutritive alfalfa hay with possibility of long time reservation in the Hexi Corridor area was achieved by alfalfa harvesting in initial flowering period,sunning for 2832 hours with tedding,and baling at the time except early morning or evening.The suggested technology will offer a scientific base for alfalfa hay curing and guide the process of alfalfa hay production in North China.