Objective: To analyze and compare composition and content of volatile oils extracted from seven samples of Ligusticum sinensis

Conioselinum tataricum and Ligusticum jeholense and observe the vascular activity of them in vitro. Method : Seven samples were collected from different producing areas.Hydrodistillation was used for the preparation of volatile oils

and was performed according to the method described in the China Pharmacopoeia (2010).The volatile oils of the seven samples were bioassayed by using KCl-induced aorta contraction assay in vitro as well as chemically analyzed by using GC-MS analysis methods

the components were quantitatively determined with normalization method. Result : eighty-two constituents from volatile oils in total were selected by GC-MS

which occupied more than 94% of included samples in average

including fourteen Common components. Moreover

the research of in vitro vaso-relaxant effect indicated that the volatile oils of all samples possessed vaso-relaxing properties with different effectiveness. and the dose-response curves were all nonlinear

its median effective dose (ED50) were in the range of 30.4-400.1 μg ·mL-1. Conclusion : Chemical constituents and the amounts of these compounds of volatile oils are varied obviously according to different samples

The vasorelaxing effectiveness is also obviously dissimilar.