Trademark as one of intellectual property has function as badge or distinctive sign from other trademark. It can be said that trademark is an asset which has a value especially for well known marks. The law number 15/2001 become stipulation to regulate marks in Indonesia. Beside that, Indonesia already ratified legal protection of trademark, which is regulated in international conventions, such as Paris Convention and TRIPS Agreement. Therefore, the study was conducted to explore, discover, and analyze how the rules for well known marks policies to provide legal certainty. By using statute approach, case approach, and conceptual approach, the authors analyze the form of protection of well known marks in Indonesia uses five indicators, the rights of well known marks, first to file system, legal protection for foreign well know marks, dispute of well known marks in Indonesia, and effectiveness factor for well known marks protection. The results show that some definitions and some important provisions in trademark law, such as well known marks and goodwill, are not strictly regulated and trademark disputes often occur because of differences in perception regarding well known marks and whether the trademark owner has goodwill in trademark registration or not.