On November 27, 2020, mainland China and the Hong Kong Special Administrative Region ("HKSAR") signed the Supplemental Arrangement Concerning Mutual Enforcement of Arbitral Awards between the Mainland and the Hong Kong Special Administrative Region (the "Supplemental Arrangement"). The Supplemental Arrangement, issued on the 20th anniversary of the formal implementation of the Arrangement Concerning Mutual Enforcement of Arbitral Awards between the Mainland and the Hong Kong Special Administrative Region (the "Arrangement"), marks a significant step forward in cooperation in arbitral award enforcement between the Mainland and HKSAR, which bears good news for both arbitration and business circles in the Mainland and HKSAR. The Supplemental Arrangement, which is concise and comprises only five articles, provides targeted amendments to the Arrangement. In this article, we briefly comment on the Supplemental Arrangement by analyzing its relevant provisions.