The sheep grazing experiment was carried out on the enclosed recovering natural grazing pastures of Dalinuorizhen of Keshiketeng Banner in Inner Mongolia in warm season to study the dynamic changes of forage nutrition contents.Different grazing systems(control,continuous grazing,4 plots rotational grazing,5 plots rotational grazing,and 6 plots rotational grazing) and two kinds of grazing intensities was made by using 2×5 complete random try design.The results showed that initial moisture,CP,EE and Ash contents in forage on no grazing area were higher than that on rotational grazing area and continuous grazing area,ADF and NDF contents were significant lower than that on grazing area;with the continuation of grazing seasons,the decline rate of forage nutritional value on no grazing area was the lowest,next the rotational grazing,last the continuous grazing;there were no significant differences in forage nutrition content among 4 plot rotation,5 plot rotation and 6 plot rotation.Grazing system and grazing intensity had interactive effect on forage nutrition contents.Therefore,rotational grazing showed superiority that with continuation of forage growth seasons,forage nutrition value could be preserved better under proper grazing intensity.