An　inverted　index　structure　of　path　that　based　on　domain　ontology　is　proposed　in　this　paper.　The　all　of　distinct　entities　in　domain　ontology　are　indexed;　and　for　each　distinct　entity　an　inverted　list,　storing　the　entity　and　the　identifiers　of　the　path　containing　the　entity,　and　experimental　results　show　that　the　index　structure　is　more　suitable　for　the　query　of　multiple　keywords　and　it　can　eliminate　the　ambiguity　and　achieve　the　semantic　expansion　of　query　keywords.