Two new compounds,schinifolin Ⅰ and acetoxyschinifolin Ⅱ,along with five known compounds(auraptenⅢ,dictamnine Ⅳ,scoparone Ⅴ,skimmianine Ⅵ,and β-sitosterol Ⅶ)were isolated from the roots of Zanthoxylum schinifolium Sieb.et Zucc.col- lected in Yixing County,Jiangsu Province.The structure determination was based upon spectroscopic analysis(UV,IR,MS,PMR,CMR,2D NMR).The structures of schinifolin Ⅰ and acetoxyschinifolin Ⅱ were elucidated as 7[(3′,7′-dimethyl-2′,6′-octadienyl)] oxy-8-methoxy-2H-1-benzopyran-2-one,and 7[(3′,7′-dimethyl-5′-acetoxy-2′, 6′-octadienyl)]oxy-8-methoxy-2H-1-benzopyran-2-one,respectively. In the test of platelet aggregation caused by PAF,compounds Ⅰ,Ⅱ,Ⅲ and Ⅴ showed inhibitory activity.