Who should retain sink credits under the Kyoto Protocol? Stakeholders expect benefits from sink credits in Japan as this question has been remained to be unclear. One objective of this article is to provide a clue to make clear the principle of retention of sink credits. A consensus building process for climate change policy package in New Zealand is reviewed. One reason that New Zealand is studied is that she has made a decision that the government holds all of sink credits, at least, during the first commitment period. As results, sink credits have an attribute as a public property, and the people, therefore, accept retention of sink credits by the government if the credits are appropriately used for public purposes. These results indicate that it is necessary to discuss not only on economic benefits but also on some technical merits/demerits due to retention of sink credits with full consideration of the principle of the Kyoto Protocol in Japan.