In the essential Oil of Ligusticum sinense Oliv cv.Chaxiong ,five phthalides with anticonvulsive activities were isolated and identified as butylidenephthalide(Ⅰ),ligustilide(Ⅱ),butylphthalide(Ⅲ),neocnidilide(Ⅳ),and senkyunolide(Ⅴ)on the basis of spectral data