The 2024 Central Economic Work Conference proposed the need to vigorously boost consumption，enhance investment returns，and comprehensively expand domestic demand. As a crucial economic growth pole in China，the Guangdong-Hong Kong-Macao Greater Bay Area serves as an important strategic fulcrum for expanding domestic demand，making the study of changes in its demand scale and structure of great practical significance. This report，based on China’s national economic accounting system and existing data，calculates the household consumption expenditure，government consumption expenditure，gross fixed capital formation，and inventory changes in the expenditure-based regional GDP of the nine Pearl River Delta cities from 2018 to 2023. These items are aggregated with the corresponding components of the expenditure-based local GDP of Hong Kong and Macao after exchange rate adjustment. On the premise that the expenditure-based regional GDP is assumed to be equal to the production-based regional GDP，the net outflow of goods and services in the GBA is derived by subtracting the aforementioned components from the latter，thereby obtaining the time-series data of the expenditure-based regional GDP and its components in the GBA from 2012 to 2023. The measurement results show that household consumption demand is the main driving force for economic growth，and the role of government consumption expenditure in stabilizing economic growth has been enhanced. Gross fixed capital formation demand has continued to grow，but issues such as the overall decline in the proportion of household consumption demand，the weakening marginal contribution of fixed capital formation demand，and large fluctuations in the net outflow of goods and services also exist. Measures should be taken to optimize the consumption environment，strengthen effective investment，and improve the trade structure to promote the high-quality economic development of the GBA.