The university of PDF used and the status of the its rapid development form a striking contrast to its low efficiency of management, semantic-based query and management for PDF must be done now.

• PDF应用的广泛性和它继续蓬勃发展的状态与对PDF文档的有效管理的滞后性形成了一对十分尖锐的矛盾，对PDF基于语义的精确查询和管理势在必行。