Component　composition　is　one　of　the　emphases　of　research　in　component　reuse.　It　can　greatly　improve　the　efficiency　and　quality　of　software　development.　Along　with　the　evolution　of　component　technology,　the　emphasis　of　system　development　has　changed　from　program　design　to　composition　based　on　the　existing　components　gradually　in　the　component-based　software　development.　The　component　library　needs　to　provide　appropriate　support　for　component　composition.　Thus,　this　paper　proposes　a　component　library　information　model　that　supports　component　composition.　On　the　basis　of　facet　classification　mechanism,　the　model　describes　the　static　information　that　component　itself　contains　and　increases　the　essential　dynamic　composition　information.　Besides,　the　composition　information　can　be　used　to　realize　complex　application　system　through　retrieval,　interface　matching　and　composing　components,　which　improves　the　reuse　rate　of　components.　©　2012　IEEE.