Abstract: A new method for simultaneous determination of cedarin,syringin,scutellarin,scoparone and coumarin was developed.The method was analyzed by Shiseido CAPCELL PAK MG II C₁₈ column (250 mm × 4.6 mm,5 μm) ,and with a gradient solvent system of water-acetonitrile.The flow was set at 0.8 mL/min.The UV detection was set with double wavelengths of 260 nm and 315 nm.The method was validated and found to be satisfactorily linear (r²> 0.999).Recoveries ranged from 98.7% to 102.5% for all compounds at three different spiking levels and relative standard deviation (RSD) was with 2.5% or less.The established method was successfully used for evaluating the quality in eight kinds of Dendrobium.

Key words: Dendrobium, phenylpropanols, coumarins, HPLC