The technology of visualization should be merged with semantic technology for abstracting and describing information from the processed DataStream, transaction data and high dimension data in the stock market. This paper proposed the ontology design in visual Stock Information System (VSIS) which combined domain information with function requirements. Firstly, use case diagram and ontology design principles of VSIS were given. Then, according to different information sources and learning theory, learning procedure, validation procedure and their interactions comprised the ontology learning cycle, whose result is VSIS top ontology pools. Next, the ontology in VSIS was defined, whose top ontology covered stock ontology, agent ontology, enquire ontology, visualization ontology, interface ontology, DB operation ontology and error processing ontology. Finally, the defined ontology was validated by Protégé.