It aims to study and compare such two Variable Data Printing (VDP) applications as traditional prepress treatment software and professional software so as to summarize the differences of the two in design approaches and output efficiency. With "Library Card" as an example, traditional prepress treatment software and professional VDP software were compared from the aspect of respective functions in VDP design by the tools of Adobe PhotoShop, InDesign and Altas PrintShop. A VDP job file in PPML format exported by PrintShop was analyzed in order to study the principle of VDP system. In conclusion, compared with the traditional prepress treatment software, the professional VDP software can not only design the VDP jobs but also output the job files in proprietary VDP format. These types of proprietary VDP formats can accurately describe the static content and variable content in print pages which can be identified by Raster Imaging Processor (RIP) of digital printers. The static content and variable content in print pages can be processed respectively by the digital printers' RIP. And the processing efficiency will be improved.