1-Alkoxy vinyl phosphonium salt is reacted with sodium salts of 1,3diketones or $\beta$ -ketoesters to give substituted 2, 3-dihydrofurans. It also reacted with diethyl-(2-phenyl-2-oxo) ethyl malonate to produce substituted cyclopentenes. And the applicability of 1-alkoxy vinyl phosphonium salt was investigated in other various reactions including the isomerization of 1-alkoxy vinyl phosphonium salt in which an acidic proton exists at the allylic position to 1-alkoxy allyl phosphonium salt, the reaction with various organometallic reagents and intramolecular cyclization via radical process.