This　paper　is　mainly　to　solve　semantic　heterogeneity　and　presents　the　method　of　introducing　ontology　into　the　process　of　establishing　patent　warning　index-system　ontology　for　the　analysis　of　patent　warning.　According　to　the　standardization　about　multi-objective　decision-tree,　the　generic　index-system　model　in　the　patent　warning　system　is　standardized　to　a　two-layer　tree　that　has　a　root　and　several　leaves.　With　the　help　of　modeling　methodology　in　domain　ontology,　the　patent　index-system　ontology　is　modeled　based　on　Description　Logic　(DL)　and　is　formalized　by　Protege　3.1.1([1]).　Finally,　the　patent　warning　prototype　system　is　established　by　Jena　and　Able.　It　proves　the　feasibility　about　patent　index-system　ontology　modeling　from　the　experiment.