In 2007 the Seoul High Court delivered the 2007Nu10541 decision which recognized that Tbroad, plaintiff, abused its market dominant position in ``TV program market`` to achieve an advantage in ``TV program service market``. In Tbroad, the Seoul High Court said that a theory of ``monopolistic leveraging`` can be applied to Tbroad`s behavior challenged by Fair Trade Commission(FTC) under the Korean Monopoly Regulation and Fair Trade Act (MRFTA). However, in 2008, the Supreme Court denied the applicability of a theory of monopolistic leveraging to Tbroad`s behavior in the question, and remanded the Seoul High Court`s decision. Of course it is true that the Supreme Court in the POSCO decision(2002Du8626) already recognized that a monopolistic leveraging theory can be accepted under the MRFTA when market dominant firm`s refusal to deal in upstream and/or downstream market matters. With regard to the Tbroad case, however, because ``TV program service market`` is neither upstream nor downstream market, and Tbroad`s behavior challenged by FTC was not ``refusal to deal``, it is hardly legitimate to apply a monopolistic leveraging theory to Tbroad`s behavior under the MRFTA and the POSCO jurisprudence as well. For this reason, the Supreme Court`s decision to remand the Seoul High Court`s decision seems definitely reasonable and right.