Ontology　is　deemed　as　an　effective　means　in　the　field　of　information　integration.　However,　environmental　data,　which　involves　various　kinds　of　data　such　as　spatio-temporal　data　about　air,　land,　water　as　well　as　non　nature　data　about　social　and　economic　issues,　is　quite　distinct　to　general　data.　Currently　how　to　use　ontology　for　environmental　data　integration　was　seldom　discussed.　This　paper　presents　the　hierarchical　structure　of　environmental　ontology　and　gives　a　method　of　modeling　environmental　data　using　ontology.　Then　an　ontology-based　GIS　framework　for　integrating　and　managing　environmental　data　is　proposed.