Abstract: A method for the determination of contents of salidroside and tyrosol in Rhodiola by HPLC was established. The HPLC separation was preformed on a KYA HIQ sil C18 column (250 mm×4.6 mm,5 μm), at flow rate 1 mL/min,with mobile phase of acetonitrile/water (1:9) and detected at wavelength 280 nm. Using uniform design, the optimal conditions for salidroside and tyrosol extraction were explored to be ultrasonically extracted by distilled water at 60℃ for 50 min.Contents of salidroside and tyrosol in Rhodiola roots were determined. Salidroside content was 2.147%, the highest in Rh. sacra from Tibet, then in Rh. crenulata and Rh. tibetica from Tibet, 1.763% and 1.271%, respectively;tyrosol content was 0.2985%,the highest in Rh. crenulata from Sichuan, then in Rh. tibetica and Rh. crenulata from Tibet, 0.2143% and 0.1836%, respectively;whereas both contents were very low in Rh. fastigiata and Rh. kirilowii from Sichuan with salidroside contents of only 0.034% and 0.003%, and tyrosol contents of 0.0164% and 0.0048%,respectively.

Key words: Rhodiola, salidroside, tyrosol, ultrasonic extraction