No, a Chinese trademark registration does not cover Hong Kong. Hong Kong has a separate legal system from mainland China, and therefore, a separate trademark registration system.
If you wish to protect your trademark in Hong Kong, you will need to file a separate trademark registration application with the Hong Kong Intellectual Property Department. However, it’s worth noting that Hong Kong and China have a mutual recognition agreement, which means that a trademark registered in China may be used as a basis for registering the same trademark in Hong Kong, and vice versa, under certain conditions.