Taking Medicago sativa as material, the effect of different cutting intensities on the quality and growth characteristics of Medicago sativa were studied. The results showed that light cutting and moderate cutting could improve the ability of plant height and regeneration. Different intensities of cutting increased the aboveground, underground biomass and root cap ratio （R/S） of Medicago sativa ,moderate cutting increased most significant,and the compensatory aboveground biomass of high cutting was the highest. With the increase of the intensity of cutting, the content of chlorophyll a increased, chlorophyll b content decreased and different cutting intensities increased the content of chlorophyll a and b comparing to pre-cutting,which could be very helpful for photosynthesis of Medicago sativa. Heavy cutting lead to the total length and mean diameter of plant roots decreased significantly （P〈0. 05） ,and moderate cutting increased the total length and mean diameter of plant roots （P〈0. 05）. Cutting also affected the activities of plant roots comparing to pre-cutting. The average crude protein,crude fat, crude fiber,crude ash and nitrogen free extract showed that moderate cutting〉light cuttingS〉heavy cutting〉control. Based on the comprehensive analysis of the indices, the optimum scheme for the quality and growth characteristics of Medicago sativa was proposed as moderate cutting in desert steppe.
Medicago sativa ； cutting intensity ； growth characteristics ； quality