Annex III to the Basic Law of the Hong Kong Special Administrative Region is the constitutional mechanism through which national laws of the People's Republic of China are made applicable inside Hong Kong. Under Article 18 of the Basic Law (1990), laws applied to the HKSAR shall be confined to those listed in Annex III, and such laws "shall be confined to those relating to defence and foreign affairs as well as other matters outside the limits of the autonomy" of the Region. On 30 June 2020 the Standing Committee of the National People's Congress (NPCSC) added the Law of the People's Republic of China on Safeguarding National Security in the Hong Kong Special Administrative Region—the National Security Law (NSL)—to Annex III, and the law was promulgated and entered into force the same evening, bypassing Hong Kong's own Legislative Council.
The mechanism works through a deliberate sequencing. Article 18 states that the NPCSC may add to or delete from the list in Annex III after consulting its Committee for the Basic Law of the HKSAR and the government of the Region. Laws listed in Annex III are applied "by way of promulgation or legislation by the Region." The NSL was applied by direct promulgation rather than local legislation, meaning it took effect without passing through Hong Kong's domestic legislative process under Article 23 of the Basic Law, which had obliged the HKSAR itself to enact national-security legislation but had remained dormant since the 2003 attempt was shelved after mass protests. The 30 June 2020 action followed the NPC's 28 May 2020 decision authorising the NPCSC to draft and enact such a law, illustrating the PRC's view that national security falls outside the autonomy guaranteed to Hong Kong.
The NSL created four categories of offences—secession, subversion, terrorism, and collusion with foreign forces—with penalties up to life imprisonment, and established new institutions including the Office for Safeguarding National Security of the Central People's Government and a local Committee for Safeguarding National Security. Article 62 of the NSL provides that it prevails over any inconsistent local law, and Article 65 vests interpretive power in the NPCSC, reinforcing PRC supremacy. Other items previously added to Annex III include laws on the national flag, national emblem, nationality, and the garrisoning of the People's Liberation Army. As of 2026 the NSL remains in force, supplemented domestically by the Safeguarding National Security Ordinance enacted under Article 23 in March 2024, completing the legislative framework Beijing had long sought.
For the China Political System paper, Annex III tests a candidate's grasp of the "One Country, Two Systems" framework, the hierarchy between the NPC/NPCSC and the HKSAR, and the limits of regional autonomy under the Basic Law. Examiners typically ask candidates to explain how Article 18 enabled the application of the NSL, to contrast promulgation with local legislation under Article 23, and to assess the implications for judicial independence and rule of law. Comparative questions may link Annex III to federal-versus-unitary distinctions and to the centralisation of authority under the PRC constitution.
Example
On 30 June 2020, the NPC Standing Committee added the National Security Law to Annex III of the Hong Kong Basic Law and promulgated it the same evening, criminalising secession, subversion, terrorism, and collusion with foreign forces.
Frequently asked questions
Article 18 of the Hong Kong Basic Law governs Annex III. It confines applicable national laws to defence, foreign affairs, and matters outside Hong Kong's autonomy, and lets the NPCSC add or delete laws after consulting its Basic Law Committee and the HKSAR government.