Abstract: In order to understand the degradation rate of the western silage, some kinds of corn silage were selected from Xinjiang and Inner Mongolia, and effective degradation rates of some nutritional components including dry material （DM）, crude protein （CP）, neutral detergent fiber （NDF） and acid detergent fiber （ADF） in the corn silage were determined by using the method of nylon bag technique so as to apply a reference for improving the utilization of corn silage in the production of the western mutton sheep. Results showed that the nutritive value of corn silage in Xinjiang was higher than that in Inner Mongolia, and the effective degradation rates of DM, CP, NDF and ADF of corn silage in Xinjiang were higher than those in Inner Mongolia, which suggested that the corn silage in Xinjiang was easier than that in Inner Mongolia to degrade in sheep＇s rumen.