Sync books between your Mac and iPhone or iPad
You can sync all or a selection of your books on your Mac to your device.
See Overview to syncing your Mac and your devices.
Sync books to your device
Connect your device to your Mac.
You can connect your device using a USB or USB-C cable or using a Wi-Fi connection. To turn on Wi-Fi syncing, see Sync content between your Mac and iPhone or iPad over Wi-Fi.
In the Finder
on your Mac, select the device in the Finder sidebar.
If you connect your device to your Mac using a USB cable and don’t see the device in the Finder sidebar, see If your device doesn’t appear in the sidebar when syncing.
Select Books in the button bar.
Select the “Sync books onto [device name]” checkbox to turn on syncing of your books.
With the checkbox selected, syncing is set to transfer all your books to your device.
To sync a selection of of books, select the “Selected books” checkbox.
Select the checkboxes for the individual books you want to sync in the books list. Deselect the checkbox for any book you don’t want to sync.
Click Books or PDFs to see your content organized by that category.
When you’re ready to sync, click Apply.
You can choose to sync your Mac and your device automatically whenever you connect them. To turn on automatic syncing, select General in the button bar, then select “Automatically sync when this [device] is connected.”
Before disconnecting your device from your Mac, click the Eject button 
in the Finder sidebar.
Remove automatically synced books from your device
To remove an unwanted book from your Mac and device, delete the book from your Mac and sync your device.
To remove a book from just your device while keeping it on your Mac, follow these steps:
Connect your device to your Mac.
You can connect your device using a USB or USB-C cable or using a Wi-Fi connection. To turn on Wi-Fi syncing, see Sync content between your Mac and iPhone or iPad over Wi-Fi.
In the Finder
on your Mac, select your device in the sidebar, then select Books in the button bar.In the books list, deselect the checkbox of the book you want removed.
Sync your Mac with the device.
WARNING: If you delete an automatically synced item from your Mac, the deleted item is removed from your device the next time you sync.
Before disconnecting your device from your Mac, click the Eject button in the Finder sidebar.