In order to elicit system requirements correctly and unambiguously, researchers in the requirements engineering community have been studying and developing a number of ontology based approaches. Many of them adopt the single ontology schema, which utilizes a global ontology to describe static knowledge for all domains. However, such ontologies lack dynamic conceptual description and they are difficult to reuse. Based on KADS knowledge modeling, this paper proposes a multiple ontology framework for requirements elicitation and reuse. Besides encapsulating the ontology of domain knowledge, it also includes the top level ontology, task ontology and application ontology. The framework provides a more powerful knowledge base for requirements elicitation and definitely defines the responsibilities of all stakeholders. The process of using the framework is discussed at last.