This research aims to analyze the sister city cooperation between Surabaya and Kitakyushu in realizing Surabaya green city through Joint Crediting Mechanism (JCM). Surabaya and Kitakyushu sister city cooperation is a strategic initiative to strengthen bilateral relations in the field of sustainable development which aims to make Surabaya a clean city, one of which is able to reduce excessive waste by using several agreed cooperation programs focused on waste management. Through the JCM scheme, it makes a significant contribution in supporting various environmental projects in Surabaya such as financial support, technology transfer and human resource exchange on sustainable development in Surabaya. Sister city cooperation has several potentials that can be utilized for the progress of the city and challenges for this cooperation to run effectively and sustainably. This approach is based on the concept of paradiplomacy, which is the involvement of local governments in international diplomacy to address global issues in sustainable development and the concept of green growth integrates through projects that support growth with environmental preservation through low�carbon technology innovation. This research aims to analyze Surabaya's sister city cooperation with Kitakyushu in realizing Surabaya green city through Joint Crediting Mechanism. Through a qualitative approach as a research design, literature analysis and interviews as data collection techniques and descriptive analysis as a research data analysis technique. The results of this collaboration have strategic planning including a focus on sustainable development and a mentoring training program between the two parties to ensure that cooperation continues and develops for the future. However, the limitation of this research is the scope of discussion that the author has only based on Surabaya government data and the lack of information from Kitakyushu government data.