A reasonable mowing system of the natural mowing steppe in Baiyinxile farm was studied. The results showed that according to N-elcment reserves per unit area, the optimum mowing period was in the middle August, and the rational rotation mowing system consisted of a year moving and the next year stopping. Under the influence of mowing, the above-ground bio-mass and density of the community decreased in a way of fluctuation year b year. The number of the fine forage grasses decreased while the forbs were bein...