Import books, audiobooks or PDFs in Books on Mac
You can import content you didn’t get from the Book Store or Audiobook Store, such as PDFs, mp3 audiobooks, Audible audiobooks and many EPUB books.
Note: Some content (such as ACSM, AZW and ODM files) can only be opened in the associated third-party app. If you’re not sure which app you need to open your book or audiobook, check with the library or eBook store that provided the content.
Go to the Books app on your Mac.
Choose File > Import.
Select the books, audiobooks or PDFs you want to import, then click Import.
You can also drag and drop books, PDFs, and some audiobooks into your library.
Note: PDFs open in Preview (or your default PDF reader), rather than in Books.
If you have imported books, purchased audiobooks and PDFs on your other devices, you can use iCloud for Books to see them on your Mac.