Abstract: We had done the experiment of Knojak mannan as antistling agent for Chinese nut from October 2002 to April in College of Forestry, Northwest Sci-Tech University of Agriculture and Forestry. Compared with contrast in four treatments, 0.3% Knojak mannan and 0.3% Knojak mannan plus 0.2% Calcium propionic two treatments made respectively respiration strength reduce 53.7% and 54.1% as well as made respectively rate of loss water reduce 34.1% and 41.3%. Chinese nut treated stored no mildew and rot at 0~2℃ for 6 months.