This study aimed to define as contronymy the phenomenon that meanings of formally the same words showed oppositional aspects with each other in Korean and examined it systematically. To attain the goal, this paper first defined what ‘contronym’ is and then arranged their semantically oppositional aspects by comparing it with the oppositional relations of vocabulary to present contronymy by types. Contronym can be divided into antonymic, complementary, and directional oppositions similarly to vocabulary relations. Complementary opposition refers to the relation of dividing into two mutually exclusive areas. In contronym, the representative example of complementary opposition can be found in binary opposition of generation and extinction, and opposition according to the sex of the reference can also be found Antonymic opposition refers to the general degree opposition. In contronym, the examples of antonymic aspects consist of contextual meanings exhibiting evaluation mostly according to either positive or negative, subjective value standards or responses. Directional opposition refers to pairs which show movement or reversion in opposition directions. These are the types that are most frequently found in contronym. These contronymy go through a historic and transitional process either turning into words like compounds or idioms or dividing into homonyms. Also, they may show grammatical opposition through the use of a certain syntactic form and can present opposite meanings in various ways according to a particular context. Especially, the ironical use functions as a crucial declaring mechanism producing new opposite relations. The use of opposite meanings of formally the same words can be seen as critical data that show the aspects of men’s essential meaning recognition and use in that it is the recognition of multiple and collective meanings realized in the process of recognizing integrated meanings.