Musical “CATS” is Andrew Lloyd Webber s world-famous musical. It has performed since 2003, in Korea, and lots of audience came to see it. The Plaintiff in the case received the license and has performed ‘CATS’ in both english version and korean version for many years with massive promotions and advertisements. The defendant “the CATS for Children” also has performed since 2003, which did not have any license but have made the advertising campaigns as if he was a legal performer with permission or sponsorship from the original musical “CATS”. The plaintiff claimed to suspend the use of title “CATS” in the defendant musical “CATS for Children” under the Unfair competition prevention act(UCPL) art. 2-1-(b). Under the Act, art 2-1-(b) provides acts of unfair competition, especially the act causing confusion with another person s commercial facilities or activities by using marks identical or similar to, another person s name, trade name, or emblem, or any other mark indicating another person s business, which is widely known in the Republic of Korea. To be applied, the act must be famous, distinctive, and cause confusion to the people in the same industry and consumers. In this case, the court admitted the claim of plaintiff, so the use of title ‘CATs’ cannot be permitted in the defendant musical “CATS for Children”. It is the first case that the use of other’s famous title is one of unfair competition acts under the UCPL. In fact, under the system of IP, the protection of title is not clear. The title cannot be protected by Copyright Act, because it was generally admitted that titles are too short to present ‘originality’. On the contrary, if the title s are sufficiently long and original, it can acquire the copyright, but it is quite rare. Meanwhile, titles cannot be easy to be registered as a trademark. because titles are descriptive on characteristic, descriptive marks cannot be registered as TM because they do not have distinctiveness as TM. To solve the increasing disputes related to titles, especially in the entertainment business, UCPL provides the protection of economic profits for famous title right owner. However there might be some limitations in applying UCLP, for excessive expansion of UCLP in titles might cause the infringement of free expression and free competitions. To develop sound environments in the entertainment business, it is necessary to employ UCLP properly in the protection of titles.