Abstract: In order to develop a new natural cigarette flavor,Undaria pinnatifida was respectively extracted by Soxhlet,microwave and supercritical CO₂fluid extractions.The obtained extracts were analyzed by GC/MS and applied into cigarette as a flavor.The results showed that:1)49 components were identified and the major components were 29-isofucosterol,methyl eicosa-5,8,11,14,17pentaenoate,hexadecanoic acid,neophytadiene,oleic acid,tetradecanoic acid,linoleic acid,ethyl linoleate,octadecanoic acid,methyl linolenate;2) the offensive odor and irritation of cigarette smoke was lowered,smoke sweetness was enhanced,and smoke taste was improved by adding the extracts;3) the extract by supercritical fluid extraction was more suitable for cigarette flavoring.