Abstract: With the plane geometry problem as the target, the subjective examination questi on solution was analyzed to built a kind of the ontologybased question solution student model method (ontologybased solution student model) so as to realize the assessment of the design of student model, provide the knowledge express method based on ontology and suitable for subjective solution, the follow method in subjective solution process, the assess method in answ er intelligence. The ontology method realizes knowledge shows. It can assessesthe situation of students mastering knowledge from a lot of respects, so as to realize guiding student studies to a certain extent.

Key words: student model, ontology, question solution