The Tripartite Environment Ministers Meeting （TEMM） is the most successful and longest-standing cooperation mechanisms within the framework of the Trilateral Summit Meeting of China， Japan and the Republic of Korea and has greatly contributed to building a clean and beautiful Northeast Asia since its launch in 1999. Especially in recent years， following the consensus in the Joint Statement on Environmental Cooperation Among China， Japan and the Republic of Korea of the 6th Trilateral Summit Meeting in 2015 （hereinafter referred to as Joint Statement）， the three countries have proactively collaborated in the initiatives advocated by the leaders of the three countries， carried out environmental policy dialogues and reached consensus on important regional and global environmental issues， making significant contributions to the improvement of the environment in Northeast Asia.In recent years， China's neighborhood diplomacy is undergoing profound and complicated changes in the external environment， especially in the Northeast Asia， an important neighboring sub-region with volatile international political landscape. Against the new situation， China has proactively promoted the relationship with neighboring countries by adhering to the principle of building friendship and partnership with neighboring countries thus to bring harmony，security and prosperity to them on the basis of amity， sincerity， mutual benefit，and inclusiveness. Since its launch in 1999， TEMM has been held every year despite all changes in the political relations among Northeast Asian countries.2018 marks the 20th anniversary for this mechanism， making environmental cooperation one of the earliest， longest-standing and most fruitful areas of cooperation among China， Japan and Republic of Korea.The past two decades has witnessed China's tremendous progress in environmental protection. The Chinese government has attached great importance to the construction of ecological civilization and has made important progress in promoting ecological environmental protection. The 19th National Congress ofthe Communist Party ofChina has made a new top-level design for ecological civilization construction and ecological environmental protection；Xi Jinping Thought on Ecological Civilization has officially been confirmed at the National Conference on Ecological and Environmental Protection； new development concepts， ecological civilization and the construction of Beautiful China have been written into Constitution of the People's Republic of China；the newly formed Ministry of Ecology and Environment has integrated all the previous functions of the Ministry of Environmental Protection together with relevant functions segmented in other six ministries. While promoting the improvement of the domestic ecological environment， China is also actively participating in global environmental governance， vigorously promoting the construction of a green \"Belt and Road\" ， sharing the concept of ecological civilization construction and green development concepts with countries along the the Silk Road， and promoting the International Coalition for Green Development on the Belt and Road and the construction ofthe Big Data Service Platform on Ecological and Environmental Protection. China stands ready to work together with the international community to promote global and regional sustainable development.