Hong Kong maintains its use of the HKD due to "one country, two systems", fiscal autonomy, and its role as an international financial hub. The decision to use HKD is made by the local government, with a balance between advantages like a buffer for China"s trade and potential risks. However, as人民币国际接受度提升 and US dollar fluctuations affect HKD, the future may see changes in the currency linkage.