Instruction can be regarded as an arrangement of external stimulus to facilitate learners in constructing knowledge. In the computer assisted learning, the stimulus is mostly the multimedia representations with instructional information. As to the mobile learning, when the representations are to be delivered anytime anywhere through the handheld devices, their formats need to be changed. Regarding this concern, the purpose of this study is to explore the design of representations in the mobile learning. This study reviews the design principles of representations and the characteristics of mobile learning, and proposes a design framework with three aspects. These aspects are based on three levels of niches of mobile technologies. The first one is the anytime anywhere delivery of instructional representations. The second one is the portability of handheld devices for guiding learning in the authentic context. The third one is to acknowledge the co-existence of informatic and social participatory in the mobile learning, where innovative pedagogy can be invented to replace the external representations in constructing corresponding mental representations. Furthermore, the roles of mobile technologies in learning are explored by addressing the relationship between mobile technologies and the design of instructional representations. With these understanding, a better mobile learning may be designed.