Abstract: OBJECTIVE To research oxidative ruthenium used in the application of the synthesis of (±)-cis-khellactone. METHODS First seselin was synthesized from 2-methyl-3-butyn-2-ol and 7-hydroxycoumarin by alkylation of hydroxy group and Claisen rearrangement. And then oxidative ruthenium was used to catalyze and oxidize seselin. Successfully, (±)-cis- khellactone was produced. RESULTS The structure was characterized by MS and NMR. CONCLUSION This study provides a new method to synthesize (±)-cis-khellactone.