Automatic　acquisition　of　ISA　relations　is　a　basic　problem　in　knowledge　acquisition　from　text.　We　present　a　method　that　acquires　and　verifies　ISA　relations　from　large　Chinese　free　text.　It　initially　discovers　a　set　of　sentences　using　Chinese　lexico-syntactic　patterns.　Then　we　combine　outside　layer　removal　and　inside　layer　gathering　for　acquiring　concepts　of　constituting　ISA　relation.　Finally,　ISA　relations　are　verified　with　semantic　features　and　context　features.　The　experimental　results　show　the　efficiency　of　our　method.　©　2008　IEEE.