Abstract: The orthogonal experiment for ammoniating rice straw at elevated temperature was arranged in a small ammoniation oven with ammonium hydrogen carbonate as ammoniating agent. The results not only show that ammonation at elevated temperature can greatly improve the nutritive value of rice straw ,but also give the effect of the two key factors of temperature and time on ammoniation results, and the interaction of them, and the optimized factorsgroup 90 ℃×15　h. In addition, based on the test of natural airdrying for ammoniated rice straw, and the contrast test of ammoniation at normal atmospheric temperature , the stability and superiority of ammoniation effect at elevated temperature were respectively investigated .