Abstract: The effects of rare earth lanthanum ( 10--40 mg/L) , salicylic acid ( 0.2--5.0 mg/L) and L - lys ( 0.5--12.5 mg/L) on the content of polysaccharides in Dendrobium huoshanense seedling were examined under tissue culture condition. The extraction condition of polysaccharides was determined. The results showed that lanthanum and L - lys had highly significant effects on the polysaccharides content, while salicylic acid had significant effects. The best concentration within each definite concentration range in improving the polysaccharides in D. huoshanense was 20mg/L lanthanum nitrate, 2.5 mg/L L - lys and 0.2 mg/L salicylic acid. The content increased 76.33% , 77. 11% and23.60% respectively compared with the control. The orthogonal test showed that the optimum plan of polysaccharides extraction in D. huoshanense was 100 mL of the content of petroleum ether, 100 mL of 80% using ethanol and 40 mL of the feed. The order of three factors to influence polysaccharides extraction was 80% using ethanol, petroleum ether, material over solvent. The above results could be used as the reference for the development and utilization of D. huoshanense resources.