Probably camphor tree (Cinnamomum camphora), somebody from your region will know for sure. If you do anymore of these indicate your region in case it improves results.
Thanks for your reply. But the Cinnamoum camphora I have seen in California is difference from the picture, is that possible it’s belong to another specie? I do some research from a book calls “check list of hong kong plants 2004”: There are 7 Species of Cinnamomum in Hong Kong: Cinnamomum appelianum Cinnamomum burmanni Cinnamomum camphora Cinnamomum aromaticum (Cinnamomum cassia) Cinnamomum jensenianum Cinnamomum parthenoxylon Cinnamomum validinerve (Cinnamomum japonicum) I believe that may be belong to one of above.