Abstract: Cutting is the main harvesting way for alfalfa and the cutting frequency affects not only the hay yield and quality but also the overwintering rate. Medicago sativa cv. Zhaodong is the main variety in Harbin and it is important to determine its cutting frequency for the alfalfa production. In twoyear cutting experiment, the hay yield, crude protein yield and overwintering rate were measured. The data of different cutting treatments were comprehensively evaluated by the gray relevancy analysis method. The results indicated that the proper cutting frequency in Harbin was 2 times per year. The correlation analysis result indicated that the cutting frequency significantly negative correlated with the productivity.