OBJECTIVE： To establish a determination method for content of polysaccharide in Acanthopanax senticosus， and to conduct cluster analysis and ultrasonic extraction technology optimization. METHODS： The content of polysaccharide in A. senticosus was determined by phenol-sulfuric acid method. Cluster analysis was conducted by using SPSS 23.0 software of the polysaccharide in A. senticosus from 17 habitats. The ultrasonic extraction technology was optimized with L9（34）orthogonal test using extraction temperature， the ratio of material to liquid， extraction time as factors， the content of polysaccharides as index， and then validated. RESULTS： The linear range of glucose ranged from 0.007 75 to 0.151 mg/mL （r＝0.999 1）； the limits of quantification and detection were 2.854， 0.856 μg/mL； RSDs of precision， stability， and repeatability tests were less than 2％； recovery rates of the sample were 98.41％-101.58％（RSD＝1.23％，n＝6）. Cluster analysis results showed that 17 batches of samples could be clustered into three classes； S1， S6， S10， S12 and S13 were clustered into one class； S3-S5 and S7 were clustered into one class； and the rest samples were clustered into one class. The optimal ultrasonic extraction technology was extraction temperature 55 ℃， ratio of material to liquid 1 ∶ 10 （g/mL）， extraction time 35 min. Results of validation tests showed the content of the polysaccharide under the best process condition was 4.36％（RSD＝0.920％，n＝3）. CONCLUSIONS： Established method is simple，reproducible and suitable for determination of polysaccharide in A. senticosus； the optimized ultrasonic extraction technology is stable and feasible.