The East Sea holds a strategic geopolitical position, making it constantly eyed by global powers. The current complex situation requires that relevant parties, especially ASEAN countries, strengthen cooperation to ensure peace and stability in the East Sea to promote economic development, especially the marine economy. The details of international cooperation in the East Sea between ASEAN countries should be in line with the UN Charter, modern international law, the UN Convention on the Law of the Sea (UNCLOS) in 1982, and the Declaration on the Conduct of Parties in the East Sea (DOC). Relevant parties have been speeding up negotiations over a Code of Conduct (COC). ASEAN countries and China officially approved the draft framework of the COC on August 6, 2016, after four years of negotiations. The 20th ASEAN-China Summit on November 13, 2017 in Manila saw Chinese Premier Li Keqiang and leaders of ASEAN countries announce the start of consultations and negotiations on the contents of the COC. It is expected to lay a firm foundation for maintaining peace in the waters. Leaders at the summit also reaffirmed the significance of implementing the DOC and suggested organising substantial negotiations on the COC soon and abiding by international law, including UNCLOS. Speaking at the summit, Prime Minister Nguyen Xuan Phuc praised the approval of the draft framework of the COC and asked relevant countries to soon organise substantial negotiations towards finalising a feasible and law-abiding document. Regarding cooperation in the time to come, he shared his advocacy for China’s initiative on building an ASEAN - China Strategic Partnership Vision to 2030, which supports the establishment of the ASEAN Community. Security issues in the East Sea are complex and unpredictable, and joint patrols are greatly needed. The naval forces of relevant parties should bolster information exchange and cooperate in building a concrete plan for joint patrols to enhance the effectiveness of activities. International cooperation between ASEAN countries is important in mitigating the risk of armed conflict and improving mutual understanding between relevant parties. Cooperation activities such as maritime control, joint patrols, drilling, marine transportation, and scientific research contribute to maintaining peace and stability in the East Sea./.