On December 20, 2015, the Order No. 665 promulgated by the State Council of the People's Republic of China published the Map of the Administrative Division of the Macao Special Administrative Region of the People's Republic of China, which clarified the scope of the water area and land boundary managed by the Macao SAR, and adjusted the administrative region of Macao SAR. Since then, the Macao SAR government has managed 85 square kilometers of water area in accordance with the law, providing strong support for the sustainable social and economic development of Macao SAR.
 
Macao SAR is rich in coastal resources and is an important part of the future development of the water area. The clear coastline location and distribution of the Macao SAR can provide key geographic information for the management and development of the water and land areas, and help the Macao SAR government to conduct the integrated sea management.
 
Coastline generally refers to the actual transition edge between water and land areas, but due to the cyclical tides, irregular storm surges, and other factors such as waves, coastal structures, and shore substances, the natural coastline has volatility.  Therefore, in order to determine the geographical location of the coastline and to apply relevant factor information in the development planning and management, it is necessary to determine the objective and stable coastline according to the regional geographical characteristics, the social environment and the coastline development status as the symbol of the regional coastline management, enabling the effective management of coastal areas.
 
In view of the above, the Cartography and Cadastre Bureau worked with various relevant departments to implement the “Coastline Survey of Macao SAR” in 2017. With the reference survey date of July 1, 2017, based on the principles of respecting history,  management status quo and considering future development, the departments formulated the coastline definition criteria in line with the actual situation in Macao SAR, adopted various advanced mapping methods to comprehensively investigate the topographical elements along the coast of Macao SAR, and collected geographic data such as the coastline location, length and types in order to establish and update the geographic information on the coastlines of Macao SAR in a standard manner.
 
Law No. 7/2018 "The Maritime Areas Management Framework Law" promulgated on of July 23, 2018 is the outline law of the Macao SAR on the management of water areas, and improves the administration system for the use, development and protection of water areas in Macao SAR. According to the Paragraph 3(5) under Article 5 of the above law, the authority of the Macao SAR Government to demarcate the coastline of the Macao SAR is defined. On August 13, 2018, the Dispatch of the Chief Executive No. 184/2018 promulgated the Coastline Map of Macao Special Administrative Region, which marked the first specification of the demarcated Macao SAR Coastline.
 
In order to record and obtain the topographic changes of the land and coastline, the Cartography and Cadastre Bureau carries out the field investigations of the coastline constantly. In response to the continuous changes in the Macau coastal environment in recent years, and with the completion of the reclamation of the New Urban Zone C in 2022, it is necessary to review the location and related geographic information of the coastline to reflect more accurately the land and sea areas of Macau. Based on the reference survey date of the coastline on January 1, 2023, the Cartography and Cadastre Bureau completed the update of the location, length and types of the coastline through on-site survey, using new 3D data collecting equipment as auxiliary technical method and consulting with various administrative authorities related to maritime management.
 
On January 8, 2024, the Dispatch of the Chief Executive No. 2/2024 promulgated the new Coastline Map of Macao Special Administrative Region, which marked the revision of the demarcated Macao SAR Coastline.