Abstract: REDD (Reducing Emissions from Deforestation and Forest Degradation) is a mechanism used by international community to eliminate the emission of greenhouse gas from deforestation and forest degradation. The function of fixing carbon by forest plays the key role in the combat to global climate change; however, developing countries are in shortage of capitals in the reduction of severe deforestation and forest degradation. Therefore, the REDD mechanism has been developed gradually in the negotiation on the climate change. The mechanism first became an international negotiation issue at the 11th Conference of the Parties to the United Nations Framework Convention on Climate Change (COP 11 to UNFCCC) in Montreal on December 2005. After ten years of efforts from international community, it was passed in the Paris COP 21 to UNFCCC in December 12, 2015, and finally signed as Paris Agreement in New York in April 22, 2016, meaning that this mechanism is finally acknowledged in the international law. In conclusion, the REDD mechanism paved the way for the international community to further strengthen the functions of forest in combating climate change, as well as for developing countries to extend forest utilization and to proceed low-carbon development.