To be able to see a progress bar during your uploads, your server must have the APC extension, the uploadprogress one, or you must be running PHP 5.4.0 or higher. Moreover, the JSON extension has to be enabled in your PHP.
If using APC, you must set apc.rfc1867 to on in your php.ini.
If using PHP 5.4.0 or higher, you must set session.upload_progress.enabled to 1 in your php.ini. However, starting from phpMyAdmin version 4.0.4, session-based upload progress has been temporarily deactivated due to its problematic behavior.
Posted in: PhpMyAdmin