And computer adaptive test based on web is one of them . cat meets irt and becomes one of the important researchs about examination system in china . we research the item bank of cat system based on web Cat是符合irt理论的,已成为国内考试系统研究的重点之一。本文就是以irt理论为指导,以c语言为研究科目进行的基于web的cat系统题库设计研究。