In the era of information revolution, the amount of digital contents is growing explosively with the advent of personal smart devices. The consumption of the digital contents makes users depend heavily on search engines to search what they want. Search requires tedious review of search results from users currently, and so alleviates it; predefined and fixed categories are provided to refine results. Since fixed categories never reflect the difference of queries and search results, they often contain insensible information. This paper proposes a method for the dynamic generation of refining categories under the ontology-based semantic search systems. It specifically suggests a measure for dynamic selection of categories and an algorithm to arrange them in an appropriate order. Finally, it proves the validity of the proposed approach by using some evaluative measures.