The　score　functions　are　often　used　to　rank　the　interval-valued　intuitionistic　fuzzy　sets　(IVIFSs)　in　multiattribute　decision　making　(MADM).　The　purpose　of　this　paper　is　to　develop　an　information-based　score　function　of　the　IVIFS　and　apply　it　to　MADM.　Considering　the　information　amount,　the　reliability,　the　certainty　information,　and　the　relative　closeness　degree,　we　propose　an　information-based　score　function　of　the　IVIFS.　Comparing　the　information-based　score　function　with　existing　ranking　methods,　we　find　that　the　information-based　score　function　can　overcome　the　drawbacks　of　the　existing　ranking　methods　and　can　rank　the　IVIFSs　well.　Three　illustrative　examples　of　MADM　with　linear　programming　are　examined　to　demonstrate　the　applicability　and　feasibility　of　the　information-based　score　function.　It　is　shown　that　the　information-based　score　function　is　well　defined　and　can　be　applied　to　MADM.