The UNESCO recommends that countries take part in the joint registration of their cultural assets within the UNESCO Convention for the Safeguarding of Intangible Cultural Heritage (2003) System for the promotion of international cooperation and culture of peace. Recently, the number of jointly registered objects has been increasing. This paper attempts to check the basis of said system and the status of its operation and propose ways of improving said system, with Korea also taking interest in the joint registration.This paper found that joint registration functions positively as an alternative to excessive competition in the individual registration of representative items of intangible heritage of humanity and to conflicts among countries over their shared cultural heritage objects. It also found that countries use joint registration as part of their strategy of registering theirs as representative items of intangible heritage of humanity, which appears to be significant from the perspective of international cooperation.This paper cites the need for a guideline that can serve as a real manual for countries taking part in joint registration to strengthen the positive functions of said system and to put the philosophy of said convention into practice.The execution guidelines of said convention have clauses concerning the expansion or contraction of joint registration, but there is no system that can convert individually registered intangible cultural heritage into joint registration. Not only is the cooperation of the State Party (Parties) necessary but also an understanding of the purpose of the Convention for the Safeguarding of the Intangible Heritage and the meaning of Safeguarding The ultimate purpose of said system of the UNESCO, i.e., invigoration of cooperation and communication between countries through shared cultural heritage, is expected to be served better by supplementing the limitation of said system.