Catalyzed　by　a　Cinchona-based　thiourea,　the　[3+2]　cycloadditions　of　barbiturate-based　olefins　with　3-isothiocyanatooxindoles　proceeded　readily,　and　furnished　dispirobarbiturates　in　excellent　chemical　yields　with　excellent　diastereo-and　enantioselectivities.　The　absolute　configuration　of　dispirobarbiturates　was　firmly　confirmed　by　an　X-ray　single　crystal　structure　analysis.　A　reaction　mechanism　was　proposed　to　account　for　the　enantioselective　formation　of　dispirobarbiturates.