Abstract: To analyze the content of total flavonoids from five species of Saussurea DC from Qinghai province，AlCl3 colorimetry was applied to determine the content of five species of Saussurea DC,the method has good linear relationship(r2=0.9986),the average of recovery was 99.10%,the RSD of precision and repeatability test were 1.15% and 1.03%,respectively.The results showed that the content of total flavonoids of five species of Saussurea DC was 9.53mg/g of S.medusa,9.45 mg/g of S.nigrescens,9.00 mg/g of S.stella,8.95 mg/g of S.katochaete,3.29 mg/g of S.medusa from high to low order and the RSD was 1.18%,0.52%,0.70%,2.15% and 0.60%,respectively.The results will provide a theoretical basis for the further studies of the medicinal herbs of Saussurea DC species.

Key words: ultraviolet spectrophotometry, Saussurea medusa Maxim, Saussurea DC, total flavonoids, AlCl3 colorimetry