Objective: To compare different chemical composition of Cinnamomi Ramulus specifications by HPLC method and discuss the relationship between specifications and chemical compositions. Method: Waters-Symmetry-RP-C18 column (4.6 mm×250 mm

5 μm) was used. The mobile phase consisted of solvent A (acetonitrile) and solvent B (0.1% aqueous phosphoric acid) by gradient elution. The flow rate was 1.0 mL·min-1. The wavelength was set at 275 nm. The column temperature was maintained at 30 ℃. Result: The calibration curves of coumarin

cinnamyl alcohol

cinnamic acid and cinnamaldehyde were in good linearity over the ranges of 0.001 32-0.132 μg(r=0.999 5)

0.001 08-0.108 μg (r=0.999 6)

0.002 57-0.257 μg (r=0.999 6)

0.141 4-1.448 μg (r=0.999 7)

and the average recoveries were 97.8%

97.2%

100.6%

99.6% with RSD of 1.5%

1.1%

1.3%

1.7% respectively. The content of coumarin

cinnamyl alcohol

cinnamic acid and cinnamaldehyde in Cinnamomi Ramulus of different specifiations was different. Conclusion: This method is simple

sensitive and accurate

which will supply evidence for the quality control and research of Cinnamomi Ramulus.