Effect of different nitrogenous fertilizer rate,mowing period and stubble height on on the production performance of Bromus inermis was studied.Results of experiment showed that with the increase of fertilizer,smooth brome production performance improved significantly.In the treatment of fertilization of 0 to 140 kg/hm²,smooth brome grass yield and crude protein content increased obviously,but they changed little within 140 kg/hm²-210kg/hm².Comprehensive comparison,the highest hay harvest combination is A₃B₁C₃ and the highest level of crude protein combination is A₃B₂C₃.