Abstract: Perception gap measures the difference between what a group/sample believe something to be (perception) and what it actually is (reality). This research examined the perception gap between how users of Hunan University Library prioritized subject services and what the librarians thought how users prioritized those services. Faculty and graduate students completed the priority selection of subject services according to the card sort grid, while the librarians ranked the same subject service cards based on how they thought faculty and graduate students would prioritize it. The perception gaps revealed several services that librarians either notably underestimated or overestimated. The services which faculty and graduate students had the most and least interest in were also analyzed.