OBJECTIVE：To investigate the effects of the integration of field processing and decoction piece processing （hereinafter called “Integration”for short ）on chemical composition of Ligusticum chuanxiong decoction pieces. METHODS ：Fresh L. chuanxiong were collected from Dujiangyan and Pengzhou of Sichuan ；integrated decoction pieces of L. chuanxiong were prepared after washing ，drying in the shade （to about 28％ moisture content ），slicing and drying ；traditional decoction pieces was prepared after drying in the shade ，adding water to moisten （to the core ），slicing and drying. HPLC fingerprints of two kinds of decoction pieces samples （with 10 batches in each type ）were established. The determination was performed on WondaSil C 18 column with mobile phase consisted of 1％ formic acid solution-acetonitrile （gradient elution ）at the flow rate of 1.0 mL/min. The column temperature was 30 ℃. The detection wavelength was set at 285 nm，and the sample size was 10 μL. Using ligusticolide A as reference ，HPLC fingerprints of 20 batches of samples were drawn. The similarity of the fingerprints was evaluated with Similarity Evaluation System for Chromatographic Fingerprint of TCM （2004A edition ），and then common peaks were confirmed. The contents of chlorogenic acid ，ferulic acid and ligusticolide A were determined by above chromatographic condition. Single factor variance analysis was performed for comparison of the contents. RESULTS ：The similarity of HPLC fingerprints among 20 batches of samples was above 0.900. A total of 16 common peaks were determined ，7 of which were chlorogenic acid ，ferulic acid，ligusticolide Ⅰ，pine cypress ferulinate ，ligusticolide A ，n-butylphthalide and ligustilide ，respectively. The linear range of chlorogenic acid ，ferulic acid and ligusticolide A were 0.008-0.200 mg/mL（r＝0.999 9），0.010-0.140 mg/mL（r＝0.999 2）and 0.100-0.600 mg/mL（r＝0.999 3）；the limits of quantification were 0.002 8，0.000 6 and 0.005 0 mg/mL，respectively；the limits of detection were 0.000 8，0.000 1 and 0.001 0 mg/mL，respectively；RSDs of precision ，reproducibility and stability tests were all lower than 3％，and average recoveries were 96.27％-102.02％（RSD＜2％，n＝6）. The contents of above compositions in the integrated decoction pieces and traditional decoction pieces were（1.677 0±0.311 0），（1.562 7±0.124 5），（9.494 0±1.351 3）mg/g and（1.300 2±0.469 2），（1.388 0±0.209 9），（9.811 7±1.098 9）mg/g，respectively；there was no statistical significance between 2 groups（P＞0.05）. CONCLUSIONS ：The chemical composition of each batch of samples of L. chuanxiong integrated decoction pieces and traditional decoction pieces is consistent ，and the content of index components as chlorogenic acid ，ferulic acid and ligusticolide A in the decoction pieces is not affected by the integration processing. This process is feasible to a certain extent.