Recent progress in wireless and sensor technologies has lead to a new development of learning environments, called context-aware ubiquitous learning environment, which is able to sense the situation of learners and provide adaptive supports. Many researchers have been investigating the development of such new learning environments; nevertheless, the criteria of establishing a context- aware ubiquitous learning environment have not yet been clearly defined. To resolve these problems, this paper presents the basic criteria, technology, infrastructure, strategies, and research issues of context-aware ubiquitous learning. Illustrative examples of conducting context-aware ubiquitous learning activities and the requirements of setting up such learning environment are also presented at the end of this paper.