Objective:To study the correlation of HPLC fingerprint on the decoction pieces and decoction of Rhizoma Ligusticum.Method:HPLC with Zorbax SB-Aq was used

acetonitrile-0.05% phosphoric acid（gradient elution）as a mobile phase

detection wavelength was at 290 nm

flow rate was 1 mL.min-1

and column temperature was 35 ℃.Result: Twenty common peaks were separated in the decoction pieces of Rhizoma Ligusticum

the similarity of 10 samples was 0.821-0.994.16 common peaks（pesk 1-pesk 16） were separated in the decoction of Rhizoma Ligusticum

the similarity of 10 samples was 0.958-0.998.The extraction percentages of 16 peaks of the decoction were 10.67%-111.63%

there were larger difference.The similarity between the decoction pieces and decoction was 0.481-0.970.Conclusion: The much composition of Rhizoma Ligusticum could be extracted by traditional decoction method.The results can provide a reference for the study of the fingerprint of Rhizoma Ligusticum

Rhizoma Ligusticum decoction or preparations containing Rhizoma Ligusticum.