An online reading processing system and method for providing interactive messages to users at end computer devices are provided, which include storing online reading information in a data storage medium; setting the online reading information with a head mark and a tail mark of at least one expert-marked key range by a setting module; reading the information after being set and hiding the head mark and the tail mark thereof; receiving the key range marked by the user; determining whether the user-marked key range covers the head mark and the tail mark so as to form interactive messages according the determination, thereby solving the drawback of failing to provide appropriate feedback or assessment according to users' behaviors as encountered in the prior techniques, and also increasing online reading interaction and enjoyment.