Abstract: The sex pheromone of Grapholitha molesta Busck was synthesized from 8-bromooctanol, triphenylphosphine and n-butylaldehyde as starting materials via Wittig reagent using dimsyl sodium in DMSO as base and solvent, followed by esterification,in an overall yield of 30%. Their structures were comfirmed by IR, NMR, MS. It is a good method with the advantage of easily obtained starting materials,short synthesized route,less by product and normal operation.