In this paper, we propose a lexical senses representation system called E-HowNet, in which the lexical senses are defined by basic concepts. As a result, the meanings of expressions are more specific than those derived by using primitives. We also design an ontology to express the taxonomic relations between concepts and the attributes of concepts. To establish the taxonomic relations between word senses, we introduce a strategy that constructs the E-HowNet ontology automatically. We then implement the lexical ontology as a Web application1 to demonstrate the taxonomy and the search functions for querying key-terms and E-HowNet expressions in the lexicon, which contains more than 88,000 lexical senses.