In the process of requirements modeling based on ontology, the obtained model description is based on application ontology; which is not easy for designer to understand and cannot be converted into requirements specification documents for design. UML is actual standard for object-oriented modeling. For this issue, this paper creates the UML meta-model, and establishes mapping rules description language for application ontology to UML meta-element, which implements the generation of UML class diagrams based on rule, use case diagrams, state transition diagram models and requirements specification documents based on UML.