It is essential to establish regional governance mechanism on basis of government's institutionalstructure, in Guangdong-Hong Kong-Macao Big Bay Area. To promote cooperation among differentgovernments of various legal systems, levels and types, it shall be the first thing to implement this urbanizationplan and transformation by central government, which involves three parts of work: first, government powershall be distributed according to one's regional functional identification as well as their cooperative structure bycentral design. Secondly, such cooperative mechanism provides a guideline for each local unit to develop inter-dependent relations with each other within this region. As the other side of the regional governance, financialcooperation mechanism to share the cost would act as a safeguard for interest sharing.