Abstract: Tactile displays for visually impaired people have problems in showing the accurate graphics information effectively.In this paper,we introduce the user study of tactile graphics design for blind students.The study starts from exploring the needs and problems that blind people meet while they are using tactile graphics,and recalls the background knowledge of related human factors,then proposes several design principles that can help designers to improve the design of tactile graphic displays.Then it shows the studies of three of our T-graphics experiments,and the analysis of the results.T-graphics greatly enhances not only the usability of tactile graphics,but also the efficiency the visually impaired accesses to graphics information.The results demonstrate the effectiveness and feasibility of these design principles.