Abstract: With low- temperature baked water chestnut peel as raw material,the polysaccharide was extracted from the water chestnut peel by cellulase. The effect of the p H,the amount of cellulase,the liquid- solid ratio,the enzymolysis temperature,and the enzymolysis time,on the extraction of polysaccharide,were studied by the single factor experiments and the orthogonal tests. The results showed that when the p H was 5,the amount of cellulase was 2.0%,the liquid- solid ratio was 30∶ 1 m L / g,the enzymolysis temperature was 60 ℃,the enzymolysis time was2 h,the extraction rate reached the maximum. Under the optimal conditions,five parallel experiments were carried out and the extraction rate could reach 32.33%,which was highly more than the extraction rate of 18.31% of water extraction method at the same conditions.The reproducibility of the experiments was good.So the cellulase method used for extraction of polysaccharide in water chestnut peel,was one kind of promising extracting method.