The next generation GPS (Dimensional and Geometrical Product Specification and Verification) is a very important basic
technique standard system for manufacturing that aims to enrich the GPS specification language to express the functional
requirements of the products, thus to reduce the correlation uncertainty and specification uncertainty, etc. On one facet, it
seems that the indication may be richer, precise, and therefore more verbose, and thus probably to take longer time for
design. And on another facet, the designer can't use the standards effectively even if he has a well comprehension of
them. To resolve the problem, this paper proposes a GPS information system, which will further help to reduce the
development cycle and the cost of the products greatly. Acquisition and representation of knowledge are one of the most difficult steps on successfully developing of the knowledge base of this GPS information system, because it affects the
development efficiency, speed, and maintenance of the system as data structure in ordinary programming. For
knowledge modeling of this GPS information system, a new modeling mechanism based on category theory is put
forward in this paper. The knowledge model based on category theory is called Geometrical Knowledge Model (GKM).
This information system is built up on the category theory due to its formality and high level of abstraction. Finally, the
basic knowledge structure of the next generation GPS roundness specification is given in the paper.