A novel ruthenium-catalyzed alkylation of cyclopropanols with sulfoxonium ylides has been developed, which afford diverse 1,5-diketones with good efficiency and broad substrate scope. To illustrate the synthetic utilities of obtained 1,5-diketones, aldol and cyclization reactions have been investigated. The preliminary mechanistic studies suggest that this process involves a sequential C-C activation and carbene migratory insertion.