Ligustral is an isomer mixture. It appears colorless to pale yellow liquid with a strong green odor. Ligustral is prepared by using 4-Hydroxy-4-methyl-2-pentanone as raw material, and then through the hydrogenation reaction and dehydration reaction to getting methyl pentadiene, and finally through the addition reaction with acrolein to obtain Ligustral. It is applied in the fragrance formulation, especially in soaps, synthetic detergent and cosmetic essence.