With the rapid development of information technology, ontology is gradually used for knowledge engineering and information science sphere. Agricultural Ontology mainly is composed of the concept and relationship between concepts in agricultural knowledge, as well as the computer can identify the composition of the formal description language. The goal of build the agricultural ontology is to form a common understanding of the agricultural information organizational structure, to known and analysis of knowledge in the field of agriculture so as to further establish the foundation for the agriculture semantic web. In this paper, we present a design principles and implementation process in vegetable products domain ontology. Through the collection and analysis of the field of vegetable products information as well as the use of inference engine, used to build vegetable domain ontology with OWL. In the information extraction prototype system, we achieved a semi-automatic filled with examples of vegetable products domain ontology. Through compared to the results before and after the use of inference engine, it show that vegetables and semi-automatic domain ontology building methods is feasible.