Hong Kong (HK) has concluded 15 bilateral investment treaties (BITs) in its name since 1992. The new development demonstrates remarkable achievements in practice of HK's external autonomy and indicates an important breakthrough and initiative in the history of BITs. Based on the provisions of HK Model BIT and relevant treaty practice, the article discusses and analyses some key provisions of HK's BITs, such as provisions on authorization, scope of application, investment treatment, deprivation and compensation, and dispute settlement. The author points out that though HK's BIT practice in general follows the traditional practice it has some characteristics due to its non-sovereign status. The great implications of HK's BIT practice are to provide the model for HKSAR, Macao SAR and Chinese Taipei, to strengthen the high autonomy of HKSAR, and to make important contributions to the development of international law.