Well, let's wait and see whether it's in a readable format after you import it. If you've done the export and import procedure correctly, there should be no problem.
But, if the address book data contains garbled characters after the export/import, I suggest exporting to CSV file format instead of address book format. The menu sequence in Address Book, to export, would be File, Export, Other Address Book, and then select Text File (Comma Separated Values).