Representing and organizing knowledge is important for a semantic knowledge searching system. To implement vegetable supply chain knowledge searching, we build three Ontologies on the base of our investigation: the vegetable supply chain domain Ontology, the user Ontology and the knowledge content Ontology. And meantimes, a metadata model is set up. we integrate these Ontologies and metadata model together by setting up the relationships of these classes. Finally we formalize the metadata by RDF (Resource Description Framework) and implement the searching system on the knowledge database of vegetable supply chain. Through the semantic searching, the users can get more suitable knowledge of vegetable supply chain.