E-books seem to be a trend and an excellent solution for mobile learning lately, but what kinds of e-books are good fit for distance learners' needs? For the purpose of offering open, more appropriate, better in quality, more convenient and flexible learning materials for distance learners. From 2011, through an experimental study on the basis of research on mobile learning ubiquitous learning and any-media, a research group at the Open University of China started to explore a new type of e-books, named "digital textbooks," sampling three experimental courses for trial; mainly getting results in four areas: definition, tools, technology and functions. The experiment is still in progress, the learning pattern centering on digital textbooks is still being explored. In conclusion, how we support different learners successfully in a digital age depends on significant ways on how well we use those new media and new technology when building smarter learning materials and learning environment.