The Basic Law (BL) is the constitutional document of the Hong Kong Special Administrative Region (HKSAR). Put into effect on July 1, 1997, it enshrines within a legal document the important concept of “One Country, Two Systems".
Q: Under the Basic Law, what is the role of the People's Liberation Army in Hong Kong?
A: The maintenance of public order in the HKSAR is the responsibility of the HKSAR Government. The People's Liberation Army stationed in the HKSAR is responsible for the defense of the HKSAR and does not interfere in the local affairs of the HKSAR. In addition to abiding by national laws, members of the garrison shall abide by the laws of the HKSAR. Expenditure for maintaining these military forces is borne by the Central People’s Government. (BL Article 14)