1. A method of building information on an emotion lexicon comprising: retrieving specific documents on the basis of a specific emotion expression lexeme to derive emotion basis lexemes of the emotion expression lexeme from sentences including the emotion expression lexeme; and deriving a new emotion basis lexeme, the new emotion basis lexeme being determined among the derived emotion basis lexemes according to at least one predefined new lexeme criterion and then storing the new emotion basis lexeme in an emotion lexicon.