Abstract: To determine the contents of the main phenolic acids and phthalides from rhizomes of Ligusticum chuanxiong during growth period.Contents of six compounds were simultaneously determined by UPLC.The conditions were as follows:column Waters BEH C₁₈ (50 × 2.1 mm i.d.,1.7 μm),mobile phase 0.1% phosphoric acid and acetonitrile using a gradient program,flow rate 0.4 mL/min,wavelength 280 and 320 nm,column temperature 35 ℃.The results of the good linear ranges were chlorogenic acid 0.78-113.64 μg/mL,ferulic acid 0.19-5.99 μg/mL,senkyunolide I 0.59-25.78 μg/mL,coniferyl ferulate 5.49-175.77 μg/mL,senkyunolide A 5.93-189.82 μg/mL and Z-ligustilide 15.88-508.18 μg/mL.The average recoveries were ranged from 98.72% to 109.63% with RSD < 3%.The method is accurate,convenient and reproducible,and it can be used for rapid determination of the main phenolic acids and phthalides from rhizomes of Ligusticum chuanxiong.In withering period,the average dry weight of rhizome was in the secondary peak,but the contents of main phenolic acids and phthalides were relatively low.In the secondary growth period of stem and leaf,the average dry weight of rhizome and the contents of main phenolic acids decreased,but the contents of main phthalides increased.In the rhizome expanding period,the average dry weight of rhizome increased quickly and reached its maximum value 26.51 ± 2.94 g at beginning of June,while the contents of the total phenolic acids and total phthalides were in relatively high levels.After that,the contents of main phenolic acids and phthalides decreased quickly.Considering the dry weight and the contents of the main compounds,the optical harvest period is from the end of May to the beginning of June in Pengzhou,Sichuan.

Key words: Ligusticum chuanxiong, phenolic acid, phthalide, content determination, UPLC