Abstract: On the basis of single factor experiments,using L9(34) orthogonal experiment,three main factors,extraction time,ratio of solid to liquid,fraction of solution volume are chosen to optimize the ultrasonic extraction method for three main component,Ilicic acid、Artemitin、Pterodontic acid,using the recovery of Ilicic acid,Artemitin,Pterodontic acid as standards.The results show that the optimum extraction process are as follow:the extraction time was 40 min,the ratio of raw material to solvent was:1:4 (g:mL),the fraction of solution volume was 90%.The method was used to treat Laggerae Herba from Dehong Mangshi，Yunnan province,from April to December,and then the content of these three active ingredients was determined by HPLC.The results showed that the content of these three active ingredients varied,at same place but different collecting time.All three active ingredients got the highest content in November.The method is accuracy,precision and stability.It can be used to extract and determine main ingredient from Laggerae Herba,instruct the optimum collecting time as well.

Key words: Laggerae Herba, ilicic acid, artemitin, pterodontic acid, content determination