A new dimeric phthalide named Z, Z’-3.3’a, 7.7’a-diligustilide was isolated from the roots of Angelica sinensis. Its structure was determined using spectroscopic methods and X-ray crystallographic diffraction analysis. A new dimeric phthalide named Z, Z’-3.3’a, 7.7’a-diligustilide was isolated from the roots of Angelica sinensis. Its structure was determined using spectroscopic methods and X-ray crystallographic diffraction analysis.