Studies on extracting technology of structure information from comparison sentences are to extract comparison target, features, and relations from given sentences and it is a very important technology in comparing search. There have been studies in English speaking countries, but this is the first study on Korean documents. In this study1, the comparison targets and relations were focused among the structure information of comparison sentences to find the superiority and inferiority determination rules. Then, the comparison keywords for superiority and inferiority as well as the predicate were used to extract superior targets among the comparison targets. Then, the comparative search results and comparative opinions are provided in a single view through the comparative search system.