Abstract: (Z)-15-tetracosenic acid,a cis-configurated monounsaturated long-chain fatty acid which has various pharmaceutical activities,was synthesized from readily available raw material,erucic acid(2).The synthesis was carried out through esterification,reduction and bromination to afford erucyl bromide 5,5 was then reacted with ethyl acetoacetate and diethyl malonate respectively to provide intermediates 6 and 7,both of them were hydrolyzed and decarboxylated to yield target compound 1 with cis-isomer content 90%.The structure of the product was characterized by NMR,IRand MS.